Sayu is pretty messed up, but our MC is kind of troubled too! He seems to have a parents complex! So the easiest solution here is for him to adopt Sayu, but that isn't that impossible as Sayu is a a runaway not an orphan?
I know about this awesome manga from a recommendation from the comment of another manga! I'm glad I clicked on that link! Thanks for the recommendation, this probably the best cross dressing manga I've ever read!
This is hard for westerners to imagine how a guy can drop a ton of dough for a date without getting the "happy ending" assured. But it's very common in East Asian cultures that the guy - especially nice guys to leave empty handed like that.