He was raped in front of shiro as a little kid by an "uncle" which I'm assuming just means older man rather than actual uncle because he had his face hidden by a mask when he was raping him. So he used rope to restrain shiro to feel safe
He was raped in front of shiro as a little kid by an "uncle" which I'm assuming just means older man rather than actual uncle because he had his face hidden by a mask when he was raping him. So he used rope to ... CatCat
So what is kii-Chan's backstory? All I know is that there was a traumatic incident at some point.