Monomi

Usami (ウサミ Usami), also known by her full name, “Magical Girl Miracle ★ Usami” (魔法の少女奇跡★ウサミ Mahō no shōjo kiseki ★ Usami), is a magical rabbit that appears as the teacher of the students in Danganronpa 2: Goodbye Despair. When Monokuma makes his appearance, she was assaulted by him, breaking her wand which grants her magical powers in the process. Her appearance was then greatly altered and her name is changed into Monomi (モノミ Monomi) without consent by Monokuma, who adopted her as a younger sister.

She was executed along with Chiaki Nanami, her artificial big sister whom were created by the Future Foundation in Chapter 5. However, she unknownly appeared during the Forced Shutdown and defeated AI Junko Enoshima.

Appearance
Usami is seen as a pure white with black eyes and has light pink blushes on her cheeks and a pink bow. Usami has white wings attached to her back and wears a pink bib with a gold charm attached to it, and wears a pink and white frilled skirt along with white stockings.

As Monomi, she looks much more like Monokuma, and much like him, she is two-toned, split down the middle. Her right side is white with one black eye, while her left side is pink and has one robotic red eye, lost from fighting Monokuma. She wears a pink diaper with three black buttons on the left and right sides and has an orange bow on her right ear.

Personality
Usami is gentle and kindhearted. As the students' teacher, she encourages them to strengthen their bonds with each other and does not like it when they get into fights. She also emphasizes the importance of caring for the environment, prohibiting the students from throwing trash anywhere on the island (because she stated if you littered it would trigger an alarm). Usami, is however, an unwitting pawn to Monokuma, often the butt of his jokes. It's no surprise that she is disliked and bullied by her students, as they never acknowledge her when she tries to catch their attention, but, on the other hand, Chiaki treats Usami like family, and Chiaki is very nice to Usami in a special way.

Island Life of Mutual Killing
In the beginning of the events of the second game, Usami introduced herself to the students as their teacher, and explained the rules of their life on the island. She also showed her magic power to the students, as example she could change a Chicken into a Cow. Later, after the students gathered their very first Hope Fragments, Usami gathered them in the beach to give them presents, which received by the few students happily, and making them trust that they were safe and sound in the island. But Monokuma soon took over, destroyed her magical staff and left her powerless after she being executed via Monobeast.

In Chapter 1, she explained numerous things to the students, such as how the old lodge was undergoing renovation or that the beach house showers did not work. She also aided Chiaki in guarding the party that was thrown by Byakuya Togami to keep Monokuma away. After every school trial, she successfully defeats a Monobeast, which allows the students to explore the other islands.

In every trial, she is hanged by Monokuma with a rope beside his private chair.

She was executed alongside Chiaki at the end of Chapter 5 where all of her remaining copies were destroyed.

At the end of Chapter 6, Usami briefly returns in her original Magical Girl appearance and single-handedly defeats the giant avatar of Junko Enoshima after the Forced Shutdown was activated. It is unknown exactly how she came back after being executed in Chapter 5 and this is even questioned by the real Byakuya Togami after they all escape the game.

Monokuma
When Monokuma shows up on the island, he adopts Usami as his little sister without her approval. She is usually beat up by Monokuma when she irritates him, which happens often. Monokuma also likes to make fun of her. He also always punches or harms her when she bothers him.

Chiaki Nanami
Both Chiaki and Usami were created by Alter Ego. They are usually trying to protect the other students from Monokuma, as seen in Chapter 1 when they stand guard outside the old lodge together. When Chiaki accidentally kills Nagito Komaeda, she is executed along with Usami.

Quotes

 * “Hue..?”
 * “I'm Usami...Magical Miracle Girl ★ Usami. I'm an itty bitty girl who's sweet like milk!"
 * “It's a place where everybody can study in peace and harmony. That's what being a student is all about.” (explaining about the library in the Second Island)
 * “In a quarrel, both sides are to blame. That's why it's better to just have no sides at all!” (to Kazuichi Soda and Fuyuhiko Kuzuryu)
 * “Um... you mentioned "imitation murder" more than once, but... what is that?” (to Nagito Komaeda)
 * “I won't forgive you!”
 * “You hate me that much?!” (to Monokuma)
 * “You stupid brother!” ('to Monokuma)
 * “Heeeey! Don't put my likeness in your movies without my permission!” (to Monokuma)
 * “I don't eat moss balls! I just enjoy looking at them!” (to Monokuma)
 * “In any case, you can't bweak the wules. Beside, it's fine if you want to have fun but don't forget your studies.”
 * “There is no need to become a famous hero. There is no need to demand the respect of others. Using such things to reproof yourself, and resent others... looking at others with jealousy. You don't have to do this. Even if others do not acknowledge it, you only need to act in a way that you can be proud of yourself! Because you yourself are your greatest fan! If you can love yourself... that love will cheer you on for the rest of your life. Love..Love..!”
 * “Bye bye! Everyone, please do not forget your teacher.”

Panic Talk Action

 * “Hajime, you stupidface!”
 * “I won't let you!”
 * “Let's all get along...”
 * “Burst open and mix!”
 * “Disappear!”
 * “I can't lose!”
 * “Don't defy your teacher!”
 * “I'll lower your grades!”
 * “Chiaki and I aren't best friends!” (Final Argument)

Trivia

 * Monomi talks in a very childish way, sometimes including chu sounds in her speech (most notably replacing the "desu" copula with "dechu").
 * In one of her many attempts to get Monokuma out of the island, she loses her eye, causing Monokuma to mockingly name her “Monomi”.
 * After Monokuma alters her, even her dialogue display, which originally labeled her Usami, immediately changes to Monomi (which also noticed by Monomi herself).
 * Oddly enough, Monomi can understand incoherent speech. She acted as the translator when Teruteru Hanamura broke down and began uttering nonsense in the first trial.
 * In the beginning of the second class trial, after the students discuss the murders which took place in Hope's Peak Academy and inspired the Twilight Syndrome Murder Case, Monokuma and Monomi (who is tied up next to his seat) get caught up in a small discussion over how violent high school students have become nowadays. The humor behind this little exchange stems for the fact that Monokuma and Monomi's voice actresses, Nobuyo Ōyama and Takako Sasuga, respectively, are both senior voice actresses who are best known for the roles they have portrayed in some of Japan's most famous, long-running animated shows since the 1970's.
 * In Chapter 2, after Fuyuhiko Kuzuryu nearly dies Monomi says: “If I could save himself myself, I would... but my magical stick is gone and I am close to powerless...” immediately after the murder of Mahiru Koizumi, Monomi apologized for not fixing the bathroom because her magical stick was gone. This most likely points to her magical stick as being the direct representation of her powers within the Neo World Program.
 * During the third Class Trial, Monokuma mentioned that Monomi eats moss balls. Monomi then reacted angrily by saying that she doesn't eat moss balls, but simply enjoys looking at them. Her reaction to Monokuma's words may be hinting that she does in fact like eating moss balls because her reaction is similar to the normal gag reactions in comedy manga/anime of a character hiding the truth by making an excuse after someone said something about the character. Either that, or Monomi indeed like watching moss balls.
 * In Chapter 4, she reveals that she, along with her brother, fears mice. Specifically, the idea of them biting her ears, pointing this out after the students were talking about the locked doors of Nezumi Castle.
 * This shared trait of Monomi and her "big brother" Monokuma is meant to further develop the intentional similarities between Monokuma and Doraemon, who is known to have had his characteristically absent cat-ears gnawed off by a robotic mouse at one point and is deathly afraid of mice ever since.
 * This trait is later revealed to be used to keep her away from Nezumi Castle if she went rogue, acting as a hiding place for the students and containing the code to enter the ancient ruins so that they can graduate and escape the program in case of that failure.
 * She makes a cameo appearance in the first game during the School Mode mini game as one of Monokuma's requested backups “Warlockkuma”. If you complete every back up that Monokuma request Warlockkuma comes alive as Usami and becomes a huge easter egg and “a mess up to the time line”, according to Monokuma. She then fights Monokuma and wins, and lets everyone leave.
 * Usami/Monomi is the only character (along with AI Junko and Chiaki) who dies in the second game.
 * She is the only known Monokuma Unit which is truly benevolent.
 * She makes another cameo appearance in Zettai Zetsubou Shoujo - Danganronpa Another Episode during the CG ending where her face appears on the side of a building above the word "Fin."
 * Monomi is the shortest character so far in the series, standing at 55 cm (1' 8), only a bit over half of Monokuma's height.
 * Beta Monomi is basically a red or pink Monokuma with deadly knives, but on the right side it has bunny ears, but still the same red/pink tone; except a diaper with a broken cartoon or realistic skull on the front (or a bow on the navel), but she still holds the knives. So Monomi was about to be evil or nice- but she kills despair with her knives and spreads hope that way, is what is said about Beta Monomi.
 * Monomi was in the Final Dead Room with Nagito, and when they finally get out, Monomi remarks she is afraid of Nagito since he tried to shoot himself when he had to play Russian Roulette as the last part of the Final Dead Room.