Kiku Nakatsukasa was born in New York City on February 28th, 2006. Toku Nakatsukasa is her older brother, and they're very much typical siblings with a typical love-hate relationship. They've lived in the same house almost their entire lives, and they're supportive of each other when they know the other needs it, but that doesn't mean they don't nag each other the other 99% of the time. Toku's been helped by his younger sister in more ways than one, and they know a good bit of the other's secrets (including that they both like boys and girls.

Kiku's lived in NYC her whole life, and she'd always been good at making friends, but she made avery good one at the beginning of 7th grade year. Anthony Stein became her partner in crime, particularly because they shared a lot of common interests (notably anime and video games, and later k-pop once she introduced him to it), but also because she wanted to set up their older siblings together. They're a mischevious duo, and are both friends with other younger siblings of some of the main characters in Middle Part. They aren't involved in any superhero shenanigans, but are involved in plenty of middle school drama.