
Bad actions can't be excused because of the background story of a person. It just bring a better understanding of why it happened. And Mioto knows it. He doesn't forgive Tsukihito because has you said he raped him and kept him locked in his room for days. Still, I think that he wants to give him a chance to become a better person who would not repeat that kind of things.
In general, everyone deal with trauma differently. Sadly, some do it by hurting people. I think we all saw some criminal minds or NYPD épisode

But...but tsukihito didn’t learn anything? I mean it seems like he did bc Mioto was like “if you do these things I’ll hate you!” And then tsuki did those things saying that he would rather be hated than let Mioto go. And then Mioto ran away and Tsuki was like searching for him bc he didn’t want to let Mioto go...but what I don’t understand is he didn’t get punished. He didn’t get hated by Mioto even though he did horrible things to him. I feel like it would have been more hmm how do i say this, interesting? No, real? If after he let Mioto go Mioto would have some kind of distance between them or idk would flinch when tsuki got close and then tsuki would understand the consequences of his actions. Of how what he did hurt Mioto and made him hate him. But that didn’t happen so even if tsuki seems like he changed actual change doesn’t happen that quickly and without realizing that he could get punished for the bad things he did. I know I put so much thought in to just fiction but I like to do that and that’s why I am so specific about the things I read lol

I understand. Like you were expecting a whole redemption arc and it wouldn't have been so bad. Maybe it will come when he will be more mature emotionally and understand everything that he did to Mioto.
Actually, I think that if Mioto didn't manage to escape at that time and stayed longer locked in Tsukihito's room he would have come to really hate him.
I'm the same as you.That's because we put so much thought in these sorties that we like them so much
Just because you had a sad childhood doesn’t justify raping and holding another person hostage. Today I watched a video on a guy that was abandoned as a baby by his biological mother and then his adopted mother (which he considered to be his real mother) died so he found his bio mother to ask her why he left him and to learn where he came from and stuff but instead he was convinced that all of the women in his life always left him behind and abandoned him so you know what he did? Went and murdered random women on the streets.
For one moment I want you to imagine if the person who found Mioto when he ran in the rain was his friend Kuze, imagine what would happen. 1) he would get help (obviously as he didn’t see his friend for weeks and now he found him like that) 2) he would be worried 3) he would be angry at Tsuki-something (as he should bc he basically kidnapped Mioto) 4) Mioto would go to a safe place
The only reason Mioto didn’t ran away further was bc it was raining, he was basically just raped and naked & he had nowhere to go. He only accepted Tsuki again bc I think he couldn’t forget the times Tsuki was nice to him (which is sad and manipulative on Tsuki’s part)
It’s not sex if it’s not consensual! It’s just rape! And rape is violence! It shouldn’t be considered different than hmm being beaten, let’s say! Imagine all the sex scenes as Mioto getting beaten and see if that still seems nice