The Madarai Brothers

The Madarai Brothers (斑井兄弟 Madarai kyōdai) are characters featured in Danganronpa/Zero.

Though originally assumed to be just a one man named Isshiki Madarai (斑井 一式) with the title Ultimate Bodyguard (超高校級の「ボディーガード」chō kōkō kyū no “bodīgādo” lit. Super High School Level Bodyguard), it is later revealed that there is actually eight identical siblings including Isshiki, Nisshiki (二式), Misshiki (三式), Yosshiki (四式), Sasshiki (五式), Rosshiki (六式), Shisshiki (七式) and Yasshiki (八式). With superhuman synchronization skills, they pose as one, their true shared talent being the Ultimate Multiple Birth Siblings (超高校級の「多胎児」chō kōkō kyū no “tataiji” lit. Super High School Level Multiple Birth Siblings).

They are mentioned to be members of Hope's Peak Academy's Student Council, however, it seems they are mostly just considered the council's bodyguards. They weren't even targets for The Tragedy of Hope's Peak Academy, which they just consider humiliating, because they were not given a chance to utilize their talent. They are portrayed as cautious and vigilant, looking for revenge for themselves and the student council.

Though not all of them were seen getting killed directly, all of the brothers were murdered by Mukuro Ikusaba.

The Madarai brothers appear in the 30-minutes long OVA, Super Danganronpa 2.5: Nagito Komaeda and the Destroyer of the World as a part of Nagito Komaeda's imagination world.

Appearance
The Madarai brothers are very tall young men with long, slender bodies, with a resemblance to a snake stretching upwards. They all have very pale skin, their faces resembling white masks. They all also have pitch-black hair dropping down to their shoulders.

All of them are characterized by lizard-like features and a skilled fighting style, their long limbs used with very swift movements. They have small and thin, almost blank lizard-like eyes, along with long tongues sticking out of their mouths. When they speak, their mouths hardly move. They all wear pitch-black school uniforms.

Personality
Contrary to his looks, Isshiki is a cautious and vigilant person, which are mentioned to be traits he was not born with, but ones that are necessary for his job. Each of the brothers are shown to be talented and have pride in their name. Ryoko Otonashi describes them as egotistical and they're easily humiliated if they feel their talent is trampled on.

The brothers are determined to have revenge for the Tragedy of Hope's Peak Academy and blame themselves for their failure to protect the student council, though it seems they're mostly just bitter because they didn't get a chance to utilize their talent as their protector. They are very vengeful, cruel and eager to harm their "prey", with a relentless predator-like personality. They also describe themselves as the type who won't go easy on someone just because they're a woman.

Their true talent, "Multiple Birth Siblings", refer to their efficient utilization of their mutual understanding, leading to extremely coordinated teamwork. Because of this talent, they tend to claim to other people that they are immortal, as they can carry on each other's work if one or more of them is wounded.

Ultimate Multiple Birth Siblings
The brothers' true talent, which allows the octuplets to expertly communicate and synchronize with each other—giving the impression that they are one individual, and not eight separate people. Because few people are aware of their true talent, this allows the brothers to give off an illusion of being 'superhuman' and 'immortal'—pretending to be in several places and once, when in reality each brother is acting separately from the others.

Ultimate Bodyguard
While hiding their true talent, the brothers all posed as a single Ultimate Bodyguard. Due to their synchronization skills they were able to protect the Student Council before the Tragedy of Hope's Peak Academy. After it he seeks revenge for the student council.

Keen Intuition
The brothers mention they have a very good intuition and they firmly believe in it. Throughout the story, they are very suspicious of Ryoko and firmly believe that she is related to the incident. In the end, it's revealed they were right, as Ryoko turns out to be Junko Enoshima, the culprit of The Tragedy of Hope's Peak Academy, but she just doesn't remember it.

Past
There is no mention of the brothers' past, but they were born as octuplets with superhuman synchronization skills.

At some point, the brothers enrolled in Hope's Peak Academy as the Ultimate Multiple Birth Siblings, but pose as one person with the talent of Ultimate Bodyguard. They were chosen to be a member of the student council, though it seems mostly to be the bodyguard for the other members, so they can relax. They seem bitter because they are considered just that.

After learning of the Tragedy of Hope's Peak Academy, the Madarai brothers seek revenge for the deceased members of the student council, but also feel very humiliated because they were not targeted during the incident and thus seemingly not considered one of the student council. They began investigating the incident, considering themselves a survivor of the student council.

Chapter 6
At night on school's central plaza, while investigating Junko Enoshima's involvement in the incident, Isshiki comes across Ryoko Otonashi meeting with Mukuro Ikusaba disguised as Junko. Though hiding, he is noticed by "Junko" and shows himself. He has a photo with him and confirms that the girl indeed seems to be Junko Enoshima. Believing that they know about the incident, he threatens the girls with supposedly cruel violence, wanting information out of them.

"Junko" duels with Isshiki and stands her ground (due to Mukuro's Ultimate Soldier talent) and orders Ryoko to write everything into her notebook. After the fight, "Junko" tells Ryoko that it's impossible for someone like her to be taken down by someone on his level, and tells her to never take her eyes off the prey. Ryoko is confused, but suddenly "Junko" disappears and leaves her alone with Isshiki.

Ryoko looks at her notebook for help, and seeing the school's Tragedy mentioned, she tells Isshiki she doesn't know anything about it. This, however, makes her much more suspicious in Isshiki's eyes. Believing that she'll die soon, Ryoko begins to think about Yasuke and how she wants to meet him, soon forgetting her fear. Noticing the change in her, Isshiki puts some distance between them. At the moment and with new composure, Ryoko is capable of using her Ultimate Analyst talent, which is written on the first page of her notebook. She believes that "power of love" granted her the talent and she tells Isshiki she is going to see Yasuke. Isshiki is confused about who she talks about, but agrees that love is a great power capable of creating both unimaginable actions and madness, though he believes Ryoko might just be feeling desperation. He says that desperate people are a bother, whether they're weak or strong.

Using her talent, Ryoko manages to run away from Isshiki. He chases after her, thinking that she truly is a strange woman.

Chapters 7-8
Ryoko manages to avoid Isshiki's attacks by running and analyzing his behavior patterns written on her notebook. She avoids him once again and he falls on the ground, but soon gets back up. Amazed, he assumes she has precognition.

Chapters 9-11
Isshiki comes to the conclusion that there's some sort of secret in Ryoko's notebook.

He chases Ryoko down into a dark shed, where Ryoko gets the upper hand and tricks him. He is flattened by fallen shelves and loses consciousness, but tells Ryoko he still has "ace up his sleeve". The second Madarai brother Nisshiki appears, attempting to knock Ryoko unconscious and break her arms and legs, but his own right arm gets broken by the real Junko Enoshima, who suddenly takes over Ryoko's consciousness. The real Junko Enoshima then kills Madarai by snapping his neck. His body is kicked several times by Junko.

It is heavily implied that the unconscious and trapped Isshiki was also murdered by Mukuro, as his brothers later mention he disappeared along with Nisshiki.

Chapter 3
The third brother Misshiki appears when Ryoko and Makoto Naegi are in Yasuke Matsuda's lab, grabbing Makoto's shoulders. After Ryoko remembers who he is, Madarai tells Ryoko that he is immortal. Makoto interrupts, asking whether he was the Isshiki Madarai of the student council, he tells them that he was a survivor of the student council and felt humiliated that he couldn't utilize his talent to protect them. He expresses that because of his role as a mere bodyguard, rebuilding the student council would be impossible, and that he can only protect the student council's remaining dignity. He threatens Ryoko by saying that if she doesn't stop lying about not knowing anything about the incident, then he would crush Makoto's head. Ryoko ignores his threat, saying it has nothing to do with her. Luckily, as Madarai is about to crush Makoto's head, Mukuro Ikusaba comes in, saves Makoto, and knocks out the third brother.

Mukuro presumably murders the third brother after the people involved leave the scene.

Chapter 10
The fourth brother Yosshiki confronts Ryoko and Kyoko Kirigiri in Yasuke's lab. Ryoko is confused about how many times she's seen Madarai get beaten up, and Yosshiki claims once again that he, "Isshiki", is immortal. However, Kyoko calls out that Isshiki Madarai's "immortality" is apparently just a ruse, much to Yosshiki's surprise. The brothers then choose to reveal their secret when the fifth brother Sasshiki appears. Kyoko speaks of how the Madarai brothers really look just like one, and the sixth brother Rosshiki soon appears to outnumber and beat up Ryoko and Kyoko.

Ryoko is pushed out of the lab into the hallway, where the seventh and eighth brothers Shisshiki and Yasshiki appear. Ryoko flees the scene by jumping out the window into the building's garden, and she is pursued by four of the brothers, with Rosshiki remaining behind in a fight with Kyoko.

Mukuro appears again, telling them not to go after Ryoko. The brothers refuse to give up, stating that they swore to avenge the student council. As Mukuro mumbles about not wanting any more victims, the brothers then ask whether she knows what happened to their three missing brothers. As the four brothers lunge at the girl in unison, Mukuro easily knocks all four of them out. Afterwards, Mukuro tries to persuade Ryoko to kill the Madarai brothers by telling her they will probably kill Yasuke once they learn of the death of last student council member who survived the incident. She also tells Ryoko that she will give her Yasuke's whereabouts as exchange. Ryoko is shocked and says she can't do it, but Mukuro then tells her that she will tell her anyway and explains that Yasuke is at the old school building. After Ryoko leaves, Mukuro takes care of the four brothers and then returns to the medical school building to kill the last brother.

Chapter 16
The Madarai brothers' deaths were covered up by the school, which claimed they had been expelled.

Super Danganronpa 2.5: Nagito Komaeda and the Destroyer of the World
The Madarai brothers appear in the OVA as a part of Nagito's imagination world.

Trivia

 * The name "Madarai" (斑井) could be roughly translated as "mottled well".
 * The name "Isshiki" (一式) is composed of the kanji 一, meaning "one" or "first", and 式, meaning "ceremony" or "rite". Each of the other siblings' given names differs only by the first character - which instead of 一 is another standard numeral between two and eight.
 * It should be noted that the readings for the given names of the Madarai siblings as they are written above are not the only possible ways to pronounce their names - as there are multiple possible readings for kanji numerals when they are used in names (nanori) - and so must not be taken as 100% accurate. The readings above were chosen due to using nanori readings that match the "elongation" of the /sh/ consonant sound of "shiki" (式) - as evident in the name "Isshiki".
 * In Danganronpa IF, Junko Enoshima pretended to have the Monokuma unit 'taken over' by "Besshiki Madarai, Ultimate Hacker."
 * This is actually a humorous reference on Junko's part to how, during the events of Danganronpa/Zero, multiple Madarai siblings would pop up under their deceased brother's identity and interfere with her plans. The joke actually stems from how "Besshiki" (別式) is written in Japanese, since the meaning of the kanji 別 betsu is "another" or "extra", making "Besshiki Madarai" as a whole mean something along the lines of "another Madarai sibling".
 * The Madarai siblings' whole appearance, from the shape of their hair to their slanted eyes and the purple shade surrounding them, makes them strikingly similar to Orochimaru, a key antagonist from the famous  Naruto series, who has throughout the course of his life achieved immortality.