
I bet nobody wants him sad, but he would definitely not betray Shinobu like that; by replacing him with his son.

Exactly what I thought! It doesn't seem like something he would do, what with having already dedicated his whole life to Shinobu... Also I don't think being with Hiraki would make Takezou any less sad, Hiraki's looks are too close to Shinobu's and I believe he'd feel a strong sense of guilt for using his brother's son like that even if it WERE what Hiraki wanted. It wouldn't be healthy, and God knows both of them would really need something other than another dysfunctional relationship.
I kinda thought that hiraki would end up consoling takezou and then they would end up together.