She's such a kid still and it exactly shows why, being an adult is not about a number, it's about responsibilities, and even if it was about a number, that number is not fucking 13 lmao.
The traditional coming of age ceremony in Japan is 20, what were you even expecting??
At this point I don't want her to end up with the teacher at all, Kurosawa would make a better fit and maybe they would both grow up a little on their own terms, at their own pace...