i think part of the appeal of tsukasa and mitsuba’s relationship is how easy it is to fall into a toxic place because you have no other options and this person is offering you something you cannot find elsewhere
even when a healthy, safe option is presented, breaking away from the stable toxic relationship is so difficult. this person is abhorrent, sure, but they’ll be there no matter what. the other person? they could vanish whenever
its also so easy to downplay your own worth. your own value. why would someone *good* stay? no one ever has before. isnt it just easier to let this awful person fill that role?
i especially enjoy the fact that tsukasa, while toxic, genuinely does show care for mitsuba in his own way. like he’s always there to share new experiences, to protect him, to pat his head and say it’ll be okay. he’s there when kou cant be, he’s there in ways kou cant be.
mitsuba, at the end of the day, isnt human. he will never *be* human. his culture is the supernatural (yokai, specifically) and tsukasa knows that world best. he can show him ways around the world he lives in. he can protect him from “worse” supernaturals, he can teach him how to survive. kou cant do any of that, how could he? he’s just a sheltered human whose never been allowed to learn anything beyond “supernatural bad”
i think the beach side story is the best example of this. kou isnt the one showing mitsuba the ocean for the first time and taking care of him. tsukasa is. for better or worse, tsukasa is his keeper and parent and big brother all wrapped up in a toxic little package
and as someone whose been trapped in those spaces before, its just so tragic to see it but i also think its more tragic that people (kou especially) treat mitsuba like he’s stupid for staying
given everything in his life, everyone whose out to hurt him, what else could mitsuba do? choose to run away and be alone and in danger? to let teru exorcise him? to let kou fumble his life for him? of course not. thats suicide and ridiculous. its safer to just… let tsukasa do what he wants. he’ll survive at least.
you dont have time to thrive when just survival is so hard to manage as it is after all