WHO IS MIKAN?
Mikan has fair skin and long, choppy, dark, plum-colored hair that is cut unevenly as a result of bullying. The longest point of her hair appears to be just past her fingertips, whereas the shortest point is slightly above her neck. Her bangs flow straight down, but are also cut at visibly differing levels. She has pale gray-mauve eyes that almost constantly convey anxiety or tearfulness. There is a beauty mark under her left eye's corner.
She wears a nurse uniform which consists of a pale pink short-sleeved shirt with a white collar and puffed sleeves trimmed with white. A short, pale blue, slightly wrinkled pleated skirt is visible underneath. Mikan wears a white apron over this which is tied behind her neck with a ribbon. It is marked with two red lines on the left side of the apron, one going down to her middle and another short red line perpendicular to the vertical one in a simple design. As well as this, she has bandages wrapped around her left forearm and hand, excluding the fingers, and around her right leg from her mid-thigh to above her ankle. Additionally, she has a square gauze band-aid on her left kneecap and wears pale pink crew length socks and white loafers.
During her high school years, she wore the standard Hope's Peak Academy uniform with off-white crew length socks. Her hair was somewhat longer, this time the longest point of her hair being her mid-thigh, and the shortest being her shoulder. Her bandages were placed differently, this time her left knee and entire right leg being wrapped along with her left forearm, as well as a band-aid being placed on her right cheek.
As the Ultimate Despair, she wears a white, old-fashioned, buttoned nurse uniform with a white nurse's cap, marked with the same red line symbol on her apron in her first appearance. This time, she has bandages wrapped around her right forearm and left leg from her mid-thigh to her ankle. She wears one elbow-length medical glove on her left arm, a glove on her right hand that cuts off at her bandages, and a black strap wrapped around her right thigh. As well as this, she wears plainer loafers and can be seen with a syringe, presumeably as a weapon of sorts.
Her childhood
Because there was no one to take care of her wounds, Mikan learned to take care of herself from a very young age. As she became more and more skilled in this area, she took an interest in nursing, realizing that it gave her a feeling of control over sick and injured people - as weaker people would have to depend on her completely, and their lives would be in her hands. Her skills in this field eventually continued to grow and she seemed to have developed almost all the necessary skills and abilities required of a nurse such as being able to give first-aid, creating various medicine/drugs, being capable of performing surgery, critical analysis of her patients condition in a moments notice and adaptability in dealing with medical emergencies.
As the Ultimate Nurse, Mikan's medical knowledge proves to be useful in murders. She provides autopsy reports, including information on the corpse's state, details on injuries, the cause of death, and time of death. Furthermore, she sometimes gives (often unwanted) health advice to others. She also appears to be more confident while she is nursing. Unlike most students, she likes being on Jabberwock Island, because her classmates acknowledge her and her talent makes her useful.
As talented as she is, Mikan's abilities as a nurse have limits; she doubted she could keep Fuyuhiko Kuzuryu alive due to the injuries he sustained during Peko Pekoyama's execution, One Woman Army. Nonetheless, her abilities are highly effective, as she was able to successfully revive Kyoko Kirigiri after the Final Killing Game, where she was near-death after using Seiko Kimura's medicine to survive her NG Code Poisoning.
Personality
Mikan is an extremely meek, paranoid and fragile individual who suffers from hazardously low self-esteem as a result of severe abuse and bullying. This has resulted in many behavioral symptoms such as being easily intimidated, breaking down and crying with little provocation, profusely apologizing and nervously stuttering while speaking. She constantly worries about annoying, boring or offending others, going so far as asking Hajime Hinata if it would be alright for her to remember his name when introducing herself. This delicate persona makes her a natural target for Hiyoko Saionji's predatory and cruel personality. However, as the Ultimate Nurse, Mikan tends to act much more confident while doing her job, and she is knowledgeable and intelligent. Her medical knowledge proves to be useful in murders, as she provides autopsy reports, including information on the corpse's state, details on injuries, cause of death, and time of death. Furthermore, she sometimes gives (often unwanted) health advice to others concerning things like eating and sleeping, and may occasionally start to describe things like bodily functions in way too much detail in her wish to give the other students' information on the subject at hand. Unlike most students, Mikan has even mentioned that she likes being on Jabberwock Island, because her classmates acknowledge her and her talent makes her useful.
Perhaps because of her high understanding of human physiology, Mikan is shown to be very skilled at reading people's faces, but she tends to over-analyze them and is quick to assume that she is disliked by those around her. She generally wants to be liked by and help other people, but her utter lack of confidence and wish to not be a bother causes her to rarely assert herself or state her feelings openly; if she feels the need, she will more than likely ask for permission from her peers to do so. This is exacerbated considerably during Class Trials, where despite her talent being incredibly useful for solving a murder, she will rarely ever speak up by her own accord. Since her social intuition is generally poor, if there is an awkward pause in a conversation, she will immediately begin to panic and apologize, believing it to be her fault. However, despite lacking many basic social skills, Mikan does actively attempt to gel with her surroundings by altering aspects of her conduct to suit what she projects as the thoughts of her peers. Notably, she appears exaggeratedly clumsy and often ends up in embarrassing and revealing poses, leading her to apologize profusely, though it's been heavily implied and even pointed out by Hiyoko that Mikan does these poses on purpose in order to gain attention and pity. Because of her insistently klutzy and cloying personality, even for all the pity and leeway she generally receives from her kinder classmates, many of them do still see her as somewhat off-putting, incompetent or irritating, causing them to distance themselves from her rather than outright mistreat her.
Because of the severe abuse she has incurred in the past, Mikan is very awkward and has a warped perception of both positive and negative social interaction. When treated with any sort of individual respect or sympathy, her first response is most often outright confusion, and sometimes assuming she has done something wrong. When first becoming friends with Hajime, she offers him to beat, strip, draw on or do other bad things to her, and states that she has done so multiple times with previous schoolmates so that they won't hate her and will continue to associate with her. She relates this to a belief that being ignored is even worse than being abused, thinking that the people who don't bully her don't care about her existence at all, a prospect that scares her much more. If someone treats her well and is outwardly kind to her in the long-term, she tends to become obsessive and cling to them, similar to the behavior of a stalker, which is interpreted as being extremely creepy (by Hajime at least), showing that she is unable to compartmentalize and reciprocate those positive feelings in a normal, healthy way. This was taken full advantage of by her supposed beloved, who turned that affection into a pathological, slave-like subservience.
By defaulting to a state of unnaturally intense submissiveness and self-deprecation as a defense mechanism, Mikan is somewhat prone to bizarre outbursts, where the repressed elements of her personality rapidly surface for brief moments before burying themselves again, usually followed by an apology for her erratic behavior. These traits include deep-seated resentment for her abusers, general frustration over how she is treated, various sadistic or otherwise disturbing obsessions, an intense yearning for control, attention and sympathy, as well as her sexual urges. During Chapter 2, she has a fleeting moment of lashing out angrily and shouting "you are done for" and "you're not gonna get away now that I've caught you" at no one in particular and seemingly completely out of nowhere, and then tries to write it off by claiming that she says nonsensical things when she's nervous. During one of the Class Trials, she also mentions that she finds a sudden urge to kill quite understandable (implying she has had such fantasies of enacting revenge on her abusers), and in Island Mode she mentions that she enjoys horror movies because of all the blood and helpless victims, especially appearing to enjoy bully characters getting what's coming for them. She also has a disturbing liking for syringes and shots, repeatedly offering them to Hajime when she gains access to the Pharmacy, and she even chases him around attempting to inject him with one during a Free-Time Event. She is also mentioned to creepily stare at Hajime after their free time together and he sometimes had a feeling that she is forever watching him from somewhere, indicating that she may have stalked Hajime. In spite of her often tightly pent-up demeanor, Mikan also shows by far the most sexual desire among all of Class 77-B's female students, particularly for Hajime. When either extremely tired or inflicted with the Despair Disease, respectively, she ends up cradling his head and falling asleep on top of him on two occasions, as well as unsubtly implying she would like to have sex with him through some brief, coy remarks. Out of the whole class, the blatancy of her sexual innuendos is only rivaled by Teruteru Hanamura.
The dichotomy of Mikan's two-faced psyche is best represented by her mixed motivations for becoming the Ultimate Nurse. Directly contrasting her abusers, Mikan sincerely wants to help those who have endured physical harm, and generally wants to assist and participate in the group. However, she has also admitted that she occasionally relishes the power she holds over the sickly, helpless people who have no choice but to rely on her and listen to her to survive. While acting as a nurse allows her to feel useful, something she doesn't normally feel, it also indulges her selfish urge to assert absolute dominance over something, a sensation she essentially never feels otherwise given her general docility. In her Island Mode ending, she openly contemplates rendering Hajime an invalid so he can stay with her forever, but he convinces her that he'll stay regardless, and thus doing so would be unnecessary. This shows Hajime's deft understanding of how Mikan manically depends on having other people around despite seeing herself as undesirable company, as well as his empathy toward her.
Due to a specific strand of the Despair Disease known as the Remembrance Disease, Mikan recovers her lost memories during Chapter 3, reverting her back to a Remnant of Despair, accompanied by a drastic personality shift which gradually reveals itself as she begins to be suspected as the blackened during the Class Trial. All of her repressed, negative and selfish traits take dominance within her, causing her to become angry, manipulative and dangerous, and in a private moment with Hajime, somewhat seductive. She is highly embittered and clearly aware of her maltreatment, and in distinct opposition to before, boldly calls the others out on it, even those who defended her in the trial but otherwise ignored her day-to-day. She angrily questions why everyone hates and bullies her, and blames her classmates exclusively for her evil deeds and transition into Despair, taking advantage of their pity in an attempt to escape her accusations all the while. Before her remembrance, Mikan was primarily self-effacing and would adapt to her environment for the benefit of others and to reduce conflict; but once the Despair Disease sets in, she is cunning and deceptive purely to preserve herself, even at the cost of the others' lives. As she turns increasingly violent and unstable, her apologizing habit still persists, repeatedly asking to be forgiven in a way that seems to be reflexive or like a mantra, but while also staunchly denying her charges to the point of angrily pulling her hair when accused. When finally backed into a corner and revealed as the culprit, Mikan ultimately finds solace in her beloved, and says that her motive for murder was simply her affection for them. She claims to no longer care about anything except that person, believing they were the only one who ever loved and accepted her. In Danganronpa 3, Mikan's brainwashed Ultimate Despair form has a resemblance to a sadistic horror nurse, and it's indicated that she tortures her victims with her medical equipment and knowledge, as well as sexually harasses them.
After awakening from her coma, Mikan reverts to her original temperament, and Junko Enoshima's brainwashing is undone. She is shown to feel guilty for her actions as an Ultimate Despair and decides to atone along with her other classmates. Notably, she is seen capable of fighting, as she rescued Hiyoko wielding a massive syringe. She also independently took care of Kyoko and saved her life. While obviously still very insecure, she now appears happier and closer with her classmates, and even has a friendlier relationship with Hiyoko.