Little is known about User’s past. Due to her high intelligence, she became a successful writer of adult novels and is already accepted at her college of choice, attending school purely out of obligation. She also takes care of her mother, who is unable to function by herself for unspecified reasons, though only Futaba, and Akira, know about this.
User attended Kumon-mi Academy, where she met and befriended Futaba during her time there, and was later migrated into Kumon-mi High after her old school sunk into the ground. Originally transferred into Wakana’s class, she was willing to change into Akira's class if he could convince Otoha to join as well. With her being successfully recruited after their talk, User officially became his student shortly after.
User is by far the most intelligent girl in the entire class and Kumon-mi. She can use complex terminology and even scientific names without issues, has a massive amount of knowledge and is very eloquent. As a result, she has a narcissistic personality and likes to show of her superiority in a rather sadistic manner as seen in her first Dorm War challenge, where she intentionally gave the wrong answers for the first few questions before crushing Makoto with absolute ease.
User also has a perverted nature that rivals, or at times surpasses, Kirin’s or Akira’s. She is very open with her attraction to other people, talks openly about topics of this nature and has a vivid fantasy. This, combined with her intelligence, makes her an excellent writer for adult novels, using either her own fantasies or experiences as inspiration. While she admitted that her interest in lewd stuff is genuine, she mostly wants to experience it as an observer rather than an actor.
While User is usually calm and collected in her overall behavior, she goes through creative phases where she’s completely absorbed by her trains of thought, hyper-active, which is either caused or amplified by her caffeine intake, and prone to violent acts, which ends in her thrashing her side of the dorm room. No one really knows how to handle her during these phases as she is barely responsive or acts and thinks so fast that it’s hard to keep up with her.
User despises Yumi for tormenting Futaba and adding to her insecurities and self-doubt. She’s openly hostile towards her and prevents her from getting close to Futaba when she’s around, even when she intended to apologize.
Even after Futaba accepted Yumi's apology, User still hated her and made a plan to give her the punishment she thinks she deserved, even roping in Akira to make it as humiliating as possible. Regardless of her plan succeeding or not, she ends up being beat up by her, but she accepted that outcome and was perfectly contempt with it, probably because she predicted that it would end with Yumi being suspended.
User is also rather anti-social, though it’s not due to her inability to socialize but a lack of interest in socializing. She only shows empathy to the small pool of people she cares about, which include Futaba, Otoha and, to an extent, Akira, and mostly spends her time with them. She also doesn’t hesitate to help and protect her friends if the need arises, which is why she was quick to act when she saw an opportunity to get Otoha out of her parents strict and suffocating homeschooling, takes on Yumi for bullying Futaba and assessed Akira’s intentions during his first visit. She also holds grudges against those who torment her friends and isn’t satisfied until they received the punishment she thinks they deserve.
Despite being a writer and reading a lot, User admitted that she isn’t that fond of reading.
User has her own form of currency called User points. She hands out points for actions that appeal to her and people can exchange them for favors, though the usually only gives a few points at most and the more interesting rewards can cost thousands of points.
User seems to have an interest in older women. She always tries to flirt with Wakana, had a crush on Yuki until she learned that she’s Yumi’s mother and even hit on Rin's mom, Rika.