Yasuke Matsuda

Yasuke Matsuda (松田 夜助 Matsuda Yasuke), is a student in Hope's Peak Academy's Class 77-A featured in Danganronpa Zero. His title is Ultimate Neurologist (超高校級の「神経学者」chō kōkō kyū no “shinkei gakusha” lit. Super High School Level Neurologist).

Appearance
Yasuke appears to be about 17 to 18 years old. undefined

He has a tall, slender and slightly lean figure, with that his face usually wears a signature apathetic gaze and this expression is more emphasized with his distinct, heavy-looking eyebrows that are usually furrowed. His face is also described as unhealthy-looking, supposedly because of stress, but he is mentioned by Monokuma to be “good-looking”. He has long-neck length messy black hair, which is mentioned to be silky and soft. His eyes are pale blue and he has long eyelashes. He is described to have a somewhat pale complexion, long fingers, and thin, small lips.

Yasuke's attire consists of a half-tucked in, dirty white dress shirt and a sloppily worn black tie that is adorned with red decals. His lower-half consists of black trousers, a belt, and bathroom slippers.

Personality
Yasuke is referred to as a “sharp-tongued brainiac” by Monokuma's memo in his profile and he's described as good-looking and intelligent. However, he is also notably sarcastic, witty and displays a perpetual, disgruntled apathy. Despite his young age, he is a very skilled neurologist and is regarded as an expert neurosurgeon and neuroscientist. He also has a short temper and when he loses it, he can be quick to resort to a stinging and bitter demeanor. While being perfectly capable of being professionally-balanced and cordial, he is also capable of putting other people in their places if not downright scaring or intimidating them.

His attitude and general demeanor often cause him to butt heads with students and staff alike, but he's more prone to brushing off their complaints and arguments not too long after they start engaging in pointless lengthy disputes.

He is quite mean and rude, carries a dry sense of humor and an unapproachable, hostile attitude. He also displays a sense of boldness and a lack of respect for those that he deems to be deserving of contempt, even if they may be indviduals of authority. A prime example of this would be The Steering Committee, and how he was able to intimidate them by fearlessly standing up to them in an intense momentum of anger. His initial rudeness and callous demeanor can be seen especially towards Ryoko Otonashi, as he constantly calls her ugly and finds himself annoyed to a practically exaggerated level. However, in spite of this, he shows some concern towards her on account of her vulnerability and forgetfulness. According to Ryoko, he may be cold and blunt, but he doesn't treat her with fake sympathy.

He seems to be quite emotionally distant, as Junko and his mother were the only close ones in his life and the process of having the two closest people to him put in unfortunate circumstances may have had a lasting and possibly permanent effect on his now presently depressed and bitter demeanor, starting with his mother whom he had to witness helplessly as she suffered and died of an illness that causes severe memory issues and followed by Junko, who was afflicted with an obsession with despair that isn't far from what his mother experienced in the sense that they were both driven insane.

Yasuke is also noted to be overly defendant of Junko, or rather her fabricated personality, Ryoko. This could possibly stem from the remainder of his mother as Ryoko, in the eyes of Yasuke, is quite similar to her on the account of her memory issues and appearance. While Yasuke appears to dislike killing and harming other people, as well as noted to hate gore, he is willing to sacrifice and risk himself and others for the sake of Junko, even if it causes him to suffer horrible guilt. He goes as far as to murder Sōshun Murasame due to him being a witness and survivor to Junko's orchestration of The Tragedy of Hope's Peak Academy.

According to Yuto Kamishiro, Yasuke's neuroticism is very well known among his classmates in Class 77-A. He also appears anxious at times and doesn't care much about his looks.

Ultimate Neurologist
Yasuke's talent as Ultimate Neurologist stems back to a traumatic incident in his childhood. When he was very young, his mother became sick and was later diagnosed with an unnamed neurological disorder, which would later cause her death. Before she died, however, her memory rapidly deteriorated, to the point where she would frequently forget who her own son was. Because of this traumatic time, Yasuke devoted himself to neurology in order to learn everything he could. As a result, he has a very broad and extensive knowledge for the human nervous system and the brain.

Memory Manipulation
As an extension of his Ultimate Neurologist abilities, Yasuke's research led him to develop an experimental treatment that allowed him to repress a person's memories from a specific time period. It was thanks to this research (along with the efforts of Chihiro Fujisaki, Miaya Gekkogahara, and others) that the Neo World Program was able to come to fruition.

Yasuke is first seen using this technique on Junko, who he attempted to protect by modifying her memories and "hiding" her behind an alternate identity, Ryoko. During its experimental stages, Ryoko had to constantly receive "treatments" from Yasuke in order for the memory-erasure to not wear off. Unfortunately, it does, and Junko regains her memories, killing Yasuke in a fit of despair.

After his death, Junko steals Yasuke's research—which she would later perfect and use on the 78th Class in order to instigate the Killing School Life.

Precise Aim
Interestingly, Yasuke is quite skilled at handling scalpels as projectile weapons by using them like throwing knives, very much similar to Sonosuke Izayoi. He throws a scalpel at Ryoko at her first arrival to his lab.

Childhood
In Yasuke's childhood, his mother was his only family. She was diagnosed with an unnamed disease that appeared to have symptoms similar to Alzheimer's disease, causing her to forget who her own son was. His mother's doctors also forbade Yasuke from addressing her as “mom” or “mother” and he was subjected to neglect, abuse and being treated as a stranger by his parent because of her constant memory loss. It's implied that all of this made him ambivalent, distant and majorly depressed, which is probably the reason why he didn't have any friends.

The mother's condition eventually led to her unfortunate death. Although Yasuke claimed that her death lifted a weight off his shoulders and made him "free", it is heavily implied that he continued to harbor a large amount of guilt and grief over her demise. Her death may also be responsible for his profession in the field of neurology, due to the bitterness felt on his behalf towards her doctors, who could have done better in his eyes.

During elementary school, Yasuke befriended Junko. Both of them didn't have any other friends and she was the closest person to him besides his mother. One day, Junko began working on a sand sculpture based on the Sagrada Familia church. However, a month later, it was destroyed by an unknown culprit. After seeing her break down in tears and weep for almost a whole day, Yasuke decided to go and search for the perpetrator. Yasuke's investigation eventually wound up to a dead-end, as he had never found any witnesses. Not being able to find out anything useful discouraged him. While he was sitting on a bench in front of the remains of the sand sculpture, Junko ran up to him with a large smile and whispered in his ear that she was the culprit who destroyed the sculpture all along, asking him to keep it a secret. When asked for a reason, she replied that she did so by accident. Truthfully, she had done this to get Yasuke out of his house, upset that his mother's condition had led him to become more withdrawn than usual.

In the years following the death of Yasuke's mother, Junko became the person that Yasuke felt he could always lean on, in fact, he didn't have any other close ones. She promised to always be there for him, which helped develop his stronger feelings towards her. She said she'll never forget Yasuke even if she forgets everything else, and that they'll always be together. For the first time in his life, Yasuke cried in front of another person, after making her promise she won't make fun of him, won't tell anyone and won't try to console him.

Shortly after his mother's demise, Yasuke began studying medicine. On his own and at a young age, he managed to become an expert physician and a full-fledged neurologist before even graduating from middle school. By the time he reached high school, he was quickly scouted to enroll into Hope's Peak. Despite the title given to him by the academy and because of his academic devotion to medicine, he was also regarded as an expert neurosurgeon and neuroscientist, with members of the school's staff acknowledging his skill and expertise. Because of this, he was often asked to run errands for the faculty or help with specific tasks they couldn't handle on their own, later being rewarded for his contributions by being granted his own laboratory in the school's dedicated Biology building and control of the aforementioned building's Neuroscience Institute in Hope's Peak Academy's eastern quarter. He was enrolled into Class 77-A, while Junko was a member of the 78th Class.

Episode 08 - The Worst Reunion by Chance
Soon after The Tragedy of Hope's Peak Academy, Yasuke is seen watching the reserve course students' riot from a window.

The Tragedy of Hope's Peak Academy
After the Tragedy of Hope's Peak Academy, Yasuke was the only student the facility trusted with the secret of their cover-up, as they needed his neurology skills for extracting and covering information from people. In exchange for his cooperation, he was awarded a large research grant and equipment for his lab.

Due to his incredible skill in neurology, Yasuke was requested by the school to assist in interrogating Junko about the incident. However, in reality, he was on Junko's side and reluctantly helped her. Junko had her memories wiped out for the purpose of testing the memory-deletion procedure meant to host Class 78th's Mutual Killing Game, as well as to hide from suspicion. She assumed the false identity of Ryoko Otonashi and became Yasuke's research subject. In good intention, to protect her from herself and to protect other people from her, Yasuke attempted to foil Junko's plans by preventing her from regaining her memories. He gave her "treatment" regularly, though, in reality, he was making sure that her condition stayed the same.

K2K System
Shortly before Danganronpa Zero, and Junko's transformation to Ryoko, Byakuya asks her if she needs a medical practitioner to examine how her brain could be so air headed. Junko mentions she already has a friend who is a neurologist so there is no need for that. At this point in the timeline, Junko also did not have access to Yasuke's memory manipulation device, and had not tested it out as Ryoko, leaving her only able to use faulty memory suppressive drugs on people when needed.

Due to the events described also being heavily obfuscated by the K2K note taking systems Unreality effect, it is unknown exactly if the events described above really happened as they are presented, or if there were any major embellishments made by the story writing AI.

Chapter 3
A month after the Tragedy of Hope's Peak Academy, Ryoko once again goes to see Yasuke for her treatment.

Yasuke throws a scalpel towards Ryoko and repeatedly insults her by calling her ugly. He then asks her who she is, claiming that he doesn’t know because he keeps looking at his manga. Ryoko answers the questions and Yasuke is surprised to find out that she remembers what just happened and what they talked, meaning that her condition might be better or maybe worse.

Yasuke gives Ryoko her treatment. Ryoko is shocked when she is reminded that she was almost suspended from school due to her bad grades, especially because it would mean she would be apart from Yasuke. Yasuke tells her he defended her because she is too valuable research subject to lose. They talk more about Ryoko's condition. Ryoko claims she isn't worried about it, and that she’s more worried about being cured because she wouldn’t get to see Yasuke anymore. Darkly, Yasuke tells her he won’t let her treatment end.

As they hear a noise outside, Yasuke explains to Ryoko about the reserve course students. He leaves to see the Steering Committee, while Ryoko sleeps in the lab.

Chapter 4
Jin Kirigiri and the Steering Committee greet Yasuke. The Steering Committee asks Yasuke to extract information from Sōshun, the second survivor of the school's Tragedy who is currently in a coma. Yasuke is angered when the Steering Committee talks about Ryoko in an insulting manner, but Jin calms down the situation and they come to an agreement.

Chapter 5
Yasuke returns to the lab and wakes Ryoko up roughly. He throws her out and tells her to come back in three days.

Chapter 12
On the dawn, Yasuke learns that Ryoko has gone missing. He looks all over for her, only to find her sleeping on his lab's bed. He ties her to the bed, to make sure she won't wander off again and she can reflect on what she did. When Ryoko refers to herself as his lover, Yasuke tells her he wouldn't have such a vermin as a girlfriend.

Angry, Yasuke lies under the bed, but he then turns silent. He sighs and says that Ryoko has always been that way and she knows the perfect ways to irritate him, referring to Junko. He tells her how in their childhood she destroyed her own sand-castle, and after hearing the frustrating story, Ryoko agrees she should be tied up. She is angry that she can't write the story in her notebook, though, but finds out it's next to her pillow. As she struggles to open it, she reads the sentence "It seems Junko Enoshima killed him —" and mention of a dead body at the central plaza. Ryoko panics about the dead body, but Yasuke doesn't seem to care about it and instead asks her if she knows who Junko Enoshima is, which confuses her. Ryoko tries to ask him if Junko is his friend, but Yasuke avoids the question and tells her that there is no body.

Ryoko can no longer reach the notebook and Yasuke tells her that Junko has nothing to do with them and she should forget about it and that all of it was probably just stories she made up. Ryoko says she would never do that because it would confuse her true memories, but Yasuke claims she must be very lonely due to her memory loss and she creates delusional stories for that reason. Frustrated about how badly she is misunderstood, Ryoko screams loudly that she is never lonely as long as she has Yasuke. She asks how he can forget that if she can remember it despite her forgetfulness. Yasuke wants to end the conversation and assures her that the notebook lies and she can believe in him instead.

Ryoko is conflicted, as the notebook and Yasuke are two the most important things to her. She decides to believe in Yasuke instead of in herself and tells him that she will give away her memories if he always stays by her side. Yasuke stays quiet for a while and answers it's impossible right now because he has other things to do. Ryoko says that his research is most important to him and he will never choose her. Yasuke says it's not it, but turns silent again. Ryoko begins to cry and asks him to at least cure her or make her forget him along with everything else, so she wouldn't feel so painful. Yasuke stands up quietly and wipes her face gently with a tissue while looking at her with lonely eyes. For some reason, Ryoko feels fear.

Silently, Yasuke turns to leave and tells her he has an appointment with another student, and that they can continue talking after he returns. After he returns, Ryoko hugs him happily as she doesn't remember their previous conversation anymore. Nevertheless, Yasuke bashfully tells her that he's sorry and unusually lets her hug him. Then, he asks how she's untied, but she can't remember anymore. As she continues to cling on Yasuke, he whispers that the reserve course students' Parade is growing louder outside. Reluctantly, Ryoko leaves back to her room.

Chapter 2
At the east compound of the school, the school's doctor guides Yasuke to see Sōshun Murasame. Yasuke asks to go alone and sees the other boy in a comatose-like state, unresponsive to his questions.

Chapter 4
Yasuke keeps talking to Sōshun and the other boy is revealed to be conscious, though nevertheless largely unresponsive. When Yasuke asks about Izuru Kamukura, Sōshun claims he killed the student council. When he asks about Junko Enoshima, Sōshun's behavior changes completely. Yasuke watches "Sōshun Murasame" stop existing in front of him, as he appears to turn completely mad, wildly screaming about Junko Enoshima and killing her.

Yasuke realizes he must protect Junko no matter the cost, even if it would cause him guilt and grudge against himself. To protect Junko and stop information about her involvement in the incident spreading, Yasuke decides to kill Sōshun and strangles to death the other boy who appears defenseless and unaware of what is happening.

Chapter 6
Sweating and anxious from the murder he committed, Yasuke tries to go see Ryoko, but she isn't in her room. He then goes to his lab and finds it has been a victim of vandalism. He sees a girl hiding under the bed, but it turns out to be Junko. They talk and Junko asks him what he is going to do now, claiming that she isn't doing anything and not seeming to be worried about the outcome. She ends the conversation with a kiss, but Yasuke turns numb and immobile as a result. Junko explains her lipstick was tainted with poison, but she also says it isn't life-threatening. Before leaving, she tells Yasuke that only he can make the choice concerning their situation. After this, Yasuke disappears, as other people cannot find him.

Chapter 12
Yasuke appears inside the old school building, in Izuru Kamukura's hiding place. He kills Yuto who was investigating in the room with Ryoko. He appears to feel bad for him, saying that maybe he would've been spared from such a fate if he didn't meddle with Junko Enoshima's affairs.

Ryoko doesn't recognize him and asks who he is. Yasuke is surprised and looks completely exhausted. Coldly, he asks why doesn't she remember him. Ryoko tries to explain that she easily forgets things, but she suddenly feels pain in her mind, as her original persona slowly begins to merge. Yasuke claims to be Izuru to test her memory and looks at her with sad eyes. Ryoko feels a bit afraid of him.

Yasuke says he has decided to talk a bit before he makes his decision. He explains that The Tragedy of Hope's Peak Academy didn't mean much for Junko, as her true goal was to brainwash the reserve course students. He says that Junko used him and the student council as sacrifices solely for that purpose. Yasuke says he didn't want to believe that she was so obsessed with despair, that he was only controlled for that purpose, and that he is involved in the incident. Yasuke then stares at Ryoko with a deadly hatred, assuming that she has remembered that he wasn't a particularly important person to her, which made her forget him. Ryoko finally realizes that he isn't Izuru and angrily he tells her that he is Yasuke.

Chapters 13-15
Yasuke tells Ryoko that Izuru has been taken away a long time ago. Ryoko is surprised that he is Yasuke, because she doesn't feel her usual feelings for him, but she confirms it with her notebook and the way he speaks. Yasuke says that she has stopped thinking about him because she has begun to remember other things. He says that his existence was never special to her and she only assumed that because she had forgotten that fact. Ryoko is confused, but then she begins to remember why she wanted to see Yasuke and how she used to act towards him. Unable to believe in anything, she begins stepping back and the wall blocks her way. Yasuke moves towards her and she feels afraid.

Ryoko tries to tell him that they should go back to how things were, but he says it's already too late and they can't go back. With a sad face, Yasuke explains that the school's tragedy made him realize that his life was just a fake scenario set up to control him. He was completely fooled by Junko, but he thought he could save her and stop her. In order to protect her, he concealed her existence itself. Regardless, she had the Steering Committee murdered, and Yasuke hid the corpses and dealt with the evidence for her sake. He confesses that he even murdered for her sake. Ryoko asks if she's that important to him and he answers that she is. Yasuke explains that the reason for that is the fact that she prevented him from being all alone after he lost his mother. She became the most important to him, even though he says she's not a lover, family nor even a friend.

When she hears how Yasuke feels about Junko, Ryoko believes she has no chance of competing with her. She lets out a deep breath and Ryoko's persona appears to begin to fade away. Suddenly, Mukuro disguised as Junko appears, saying that she just came to provide the supplementary explanation. Ryoko remembers Mukuro's face and Mukuro explain she has just been following Junko's orders. Yasuke understands that Junko anticipated his actions and he angrily says that she is now spectating his actions in amusement. Ryoko is confused by their words and is already incapable of understanding Yasuke's feelings. However, she understands that he both loves and hates Junko. Ryoko realizes that she can only give up and let her and Yasuke's world end.

Yasuke lets out a huge sigh and then, eyes brimming with determination, says that he must end this. He says that his desire to protect Junko was likely true despair and his despair won't end unless he ends this. He says he desperately tried to hide her and not have her involved with others, thinking he could protect her. However, it was pointless, as his actions meant nothing to Junko. In the end, she could only inflict despair on anyone involved with her. He says it's despair that he finally understands this.

Deciding to end everything, Yasuke attempts to strangle Ryoko to death, saying that it's for his and not Junko's sake. Once again, Ryoko hallucinates, seeing and hearing Junko's figure. As she imagines Junko's face, she finally remembers that it is her own face. At that very moment, "Ryoko Otonashi" stopped existing, replaced by her original persona. Junko laughs, saying that Ryoko never existed in the first place.

Suddenly, Junko stabs Yasuke in the side with a knife. Quickly dying from the wound, Yasuke tells her that he lied to her and that his "treatment" had prevented her from remembering. However, Junko already knows this. Yasuke asks her why she pulled the whole turn of events, assuming that she wanted to pull him into despair, as he was the one who always thought of her. Junko gently caresses his face, but then denies his words angrily and pulls her hand away. Yasuke collapses in the pool of his own blood, realizing that Junko truly doesn't care about him. Before his death, Junko bluffs that it was her who was responsible for the death of his mother, however, it's unknown if she was actually responsible or just said this to pit Yasuke further into despair during his final moments. Junko refuses to answer him and he dies with never knowing the truth.

After Yasuke's death, Junko lets out her true feelings and feels sadness, as he was the most important to her of all. She kicks his body until it's a bloody unrecognizable mess, laughing and crying, as she feels the incredibly strong despair of murdering her loved one.

Danganronpa 2.5: Nagito Komaeda and the World Vanquisher
Yasuke appears as a cameo in the OVA, was shown with Ryoko and Isshiki.

Danganronpa: Trigger Happy Havoc IF
Yasuke is mentioned at the end of the short story to be the one who made the machine that can erase and restore memories.

Relationships
Family:

His mother
Yasuke's mother is said to be the closest person to him aside from Junko. It is assumed that his relationship with his mother before her disease was peaceful, however, it was severely strained after she was diagnosed with a fatal illness that is implied to be Alzheimer's disease. The symptoms included long-term memory loss which resulted in her not being able to recognize her own son and being thrown into hysteria which led to possible abuse and neglect on her own son. After she passed away, Yasuke was thrown into a pit of depression and grief.

He often displays traits signifying that he holds grief and bitterness towards the doctors who in his eyes, could've done a better job of saving her life. It is most likely this traumatic event in his childhood that led him to pursue into the field of neurology to which he excelled at.

Childhood:

Junko Enoshima
Junko is Yasuke's childhood friend, as well as the closest person to him besides his own mother.

They became friends during elementary school and neither of them had any other friends. One day, Junko began working on a sand sculpture based on the Sagrada Familia church. However, a month later, it was destroyed by an unknown culprit. After seeing her break down in tears and weep for almost a whole day, Yasuke decided to go and search for the perpetrator. Yasuke's investigation eventually wound up to a dead-end, as he had never found any witnesses. Not being able to find out anything useful discouraged him. While he was sitting on a bench in front of the remains of the sand sculpture, Junko ran up to him with a large smile and whispered in his ear that she was the culprit who destroyed the sculpture all along, asking him to keep it a secret. When asked for a reason, she replied that she did so by accident. Truthfully, she had done this to get Yasuke out of his house, upset that his mother's condition had led him to become more withdrawn than usual.

In the years following the death of Yasuke's mother, Junko became the person that Yasuke felt he could always lean on. In fact, he didn't feel close to any other people. She promised to always be there for him, which helped develop his stronger feelings towards her. She said she'll never forget Yasuke even if she forgets everything else, and that they'll always be together. For the first time in his life, Yasuke cried in front of another person, after making her promise she won't make fun of him, won't tell anyone and won't try to console him. He became dependent on her and ready to do anything for her, because she told him she'll be what's important to him for now and prevented him from being all alone when he needed it the most. Junko also had a tendency to call them "lovers" and had romantic feelings for Yasuke, but he denied this with annoyance and called her a "stalker", treating her very similarly like he does Ryoko later in life. Yasuke has described Junko as "not family, a lover or even a friend ... but someone just as important (to him) as any of those".

Both of them later enrolled in Hope's Peak Academy and after the school's tragedy, Yasuke reluctantly assisted Junko in her plans, creating her alternative identity Ryoko Otonashi. He wanted to prevent her from ever remembering her obsession with despair in order to protect not only herself, but also the rest of the world. However, Junko had already planned ahead and had Mukuro act out murders in the school on her behalf. Despite not enjoying despair and killing, Yasuke was willing to do bad things for the sake of protecting Junko, even if it caused him to feel horrible guilt.

Their relationship appears to be characterized by codependence on one another, which leads to each party acting with unhinged devotion. One of Yasuke's main goals throughout the novel is to keep Ryoko from remembering her true self, which he sees to be a means of protecting her. His other goal is to cover up the true orchestrator of the Mutual Killing of the Student Council, another means of protecting Junko. Yasuke has a strong set of morals, though those morals only seem to apply to those he loves. He demonstrates this by silencing Sōshun Murasame, murdering him so that he cannot reveal Junko's involvement. He even sees this as an act of kindness, saying that Sōshun was so far gone in his despair that he had become a monster. It seems Yasuke cares little for his own well being or may actively be self-destructive for the sake of Junko. Admidst his cynical pessmistic view of the world, he remains certain that he will succeed in saving Junko from herself, thus preventing any further tragedy.

Towards the end of the novel, he seems to realise exactly how toxic and corruptive the inner workings of his relationship with Junko is. Finally, Yasuke understands and admits to himself that Junko has only been using him. He is frustrated by her love for despair and he's angered when he comes to the conclusion that she never cared about him. He states that he both loves and hates her, and eventually he decides to kill her whilst she is still Ryoko. However, he ends up being the one killed by Junko in a fit of despair; as he is one of the people she cares about the most. He was stabbed in the abdomen by Junko and afterward she kicked his body until it was rendered mutilated and unrecognizable. He died believing that Junko did not care about him at all, but in truth, this was not the case. Junko felt painful grief for his death and let him die in despair for the sake of increasing her own despair.

Ryoko Otonashi
Ryoko is the alternative, amnesiac identity of Junko. Even though she has constant memory issues, she is still in love with Yasuke.

From the beginning, Yasuke treats her condescendingly, berates her, and often makes fun of her whenever he has a chance to. On the other hand, Ryoko is infatuated with him and holds a deep liking towards him despite his sharp tongue. She acts clingy when she is around him and constantly whines when he's present. It's stated that she likes Yasuke because he doesn't treat her with fake sympathy. There are times when Yasuke is shown to warm up towards Ryoko, even appearing gentle towards her when she cries about her painful situation. At one point he ultimately apologized for getting angry.

On the note of her amnesia and treatment, Yasuke is shown to be, if not intensely protective of Ryoko, then quite defensive for her. This is shown when one of the old men of the Steering Committee insults Ryoko for being a “dunce with no hope of recovery” and reckons her to be a failure. This causes Yasuke to respond in contempt, yelling at one of the committee members to “shut the fuck up” and that his “dirty mouth talks too much”. He proclaims that he is the only one allowed to make fun of Ryoko.

During his untimely end, Yasuke is revealed to have been protecting Junko's alternate identity (Ryoko) from herself by planting fake information inside of her notebook. He even attempted to kill Ryoko before she regained her memories. However, this failed miserably when she fell into a fit of despair and killed him after realizing who she truly was. The motive for his murder was simply the desire to drive herself further into despair by killing one of the two people she loved the most: Yasuke and Mukuro Ikusaba, whom Junko later kills during the killing game of Class 78.

It has been stated that Ryoko especially is very similar to Yasuke's mother concerning her appearance and memory issues, which might be one of the reasons why he's fond of her.

Collaborators:

Miaya Gekkogahara and Chihiro Fujisaki
They are fellow prominent collaborators in creation of the Neo World Program.

Trivia

 * “Yasuke” (夜助) is composed of 夜 - “evening” or “night” and 助 - meaning “help” or “rescue” which most likely refers to the fact that he attempted to protect Junko Enoshima from being caught as the mastermind and all the while as he attempted to keep her from regaining her memories for the purpose of preventing the following events of Danganronpa: Trigger Happy Havoc.
 * “Matsuda” (松田) translates to “rice field of pine”.
 * According to dialogue between the two, Ryoko had bugged Yasuke to watch the movie  starring for some time, yet always mistakenly referred to him as "Wacoal Culkin".  is a manufacturer of women's lingerie and underwear, founded in 1949 in Japan by Koichi Tsukamoto.
 * He mentions that he dislikes gore.
 * Yasuke likes reading manga. The manga pictured in his official art is titled Comic PonPon (コミックボンボン), which is parody of real-world childrens' manga magazine Comic BomBom (コミックポンポン), known for publishing many video game spin-off manga series, including Megaman, who features on the parody comic's cover. One of the creators for this manga, Eiichirō Saiyama, is introduced in Danganronpa Gaiden: Killer Killer.
 * Yasuke was referenced in one of the Nonstop Debates in the last Class Trial of Danganronpa 2: Goodbye Despair, "Wh*re's Yasuk=?". Interestingly it appeared after Alter Ego Junko revealed Hajime Hinata's true identity as Izuru Kamukura.
 * Though not mentioned by name, during Junko Enoshima's Winter seasonal event with Mukuro Ikusaba in Danganronpa V3: Killing Harmony's Ultimate Talent Development Plan, Junko mentions how boring it was to watch her "childhood friend" (Yasuke)'s graduation and how boring it was that he seemed so happy.
 * The bathroom slippers Matsuda is pictured wearing bear an incredible similarity to the VIC 510 slippers made by the Nishibe Chemical Company. These sandals are made using antibacterial material that is both water and chemical resistant and can be easily disinfected. These slippers are also worn by doctors in operating rooms due to having these qualities.

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