Decided to rewatch blue bday, and damn, it really sparked back my hatered for Kaito fans who don't even bother to pay attention to Aoko. They all hate on Aoko or villanize her for using his phobia against him (which yeah, its not nice) but completely ignore the fact that Kaito does the same back??
Aoko is already incredibly uncomfortable about how unfeminine she is, what with her short fuze, and the way she can easily throw desks or chairs. She is not unhappy about being a tomboy, its a key part of who she is, but she still is a girl, and wants to be seen as one. Kaito though keeps mentioning how unfemine she is, how she "lacks the physique" or "doesn't act like one".
I know he's teasing, I know it's his way of showing that he's looking out for her, but as perceptive as Aoko is, as much as she knows, being insulted for something you already blame yourself for is not fun. I know first hand, especially when it comes to a body that you can't change.
Kaito also keeps mentioning how she acts like a child, (which, yes!!! you are both children!!) as if he is ignores just how mature Aoko can be. Aoko lives practically on her own, is mature about the ways she reacts to her parents choosing work over her, and does her best to not let her emotions or rumors affect how she treats people. Kaito is aware of this, even respects her for this, and tries to put his trust in her taking KID well because of this emotional maturity. Except he doesn't show it.
Kaiao is not meant to be a perfect relationship, whether just as friends, or as more. Kaiao is about the trust they built from being by eachothers sides for so long, and seeing eachother at their lowest. They know how they deal with greif, and they support eachother through it. They know how they act on off days, and will guess how they want to be treated for the day accurately.
TLDR: Kaito's character cannot be understood without a deep understanding of Aoko's character, and I need people to realize this so bad. They are both kids, they will use each other's weaknesses to their advantages, that's just how their relationship works. Painting Aoko as a villain for using his phobia, when he does the exact same thing back is completely unfair towards the both of them.