Kazuki is Miki's 13-year-old brother who lives with their father. He first appears in the opening credits and gets a proper introduction in episode 2, where he poses as Miki's boyfriend to keep other guys from hitting on her.
He's got some health issues that worry him—he's afraid his sickness will hold him back from doing the things he actually wants to do. Miki encourages him through it though. Despite his health concerns, Kazuki dreams of becoming a doctor someday.
Content compiled by AnimeList.moe from publicly available sources.
