Koito's the type who comes across as bold and confident at home but turns into a nervous wreck anywhere else—think small, skittish animal energy. She's genuinely hardworking and sharp when it comes to schoolwork, which makes sense given her strict upbringing; her parents pushed the honor student thing hard, so she missed out on a lot of normal kid stuff. She's never even been to a Halloween party, which she's mentioned before. Still in her first year of high school, she tends to get easily tricked by her childhood friends and is often the target of their teasing.
There's a contradiction in how she sees herself versus how she actually is. Koito wants to be the mature, responsible one holding her friend group together, and she'll definitely put on a confident or boastful front to prove it. But that tough exterior cracks pretty easily—her timid, kind of childish side comes through all the time, especially when she's startled. The thing is, even as she's trying to play the responsible role, she deals with real self-doubt about how much harder she has to work than her peers to make it as an idol. That pressure from her past doesn't just disappear.
Content compiled by AnimeList.moe from publicly available sources.