Any sort of disability works. As long as he's looked down upon by people even the female lead at first. Eventually she gets past that and falls for him. Love triangles a plus especially if the other guy tries to act superior to the male lead because he's not disabled.

Can't See Can't Hear But Love - this one has multiple love triangles
Kingyo Sou
Taisho Wotome Otogibanashi

You can also try Perfect World (Aruga Rie)