I think I watched it too close to bingeing on samurai novels, because in samurai culture that stuff can also be for a brotherly relationship or a mentor/student relationship, or just close friends. (and granted, as long as those weren't blood relationships, that would also sometimes involve sex, as there really wasn't much concept of sexual orientation at the time) That said, written today, yeah, it was probably meant to be seen as OTP, it's just that watching it, especially in the context of both with the bratty main character(ok, he got better, but really, it's a miracle his brother didn't kill him long ago) I never really saw it as such.