Does anyone know of any manga where the relationship is straight, but the boy is like an uke from a yaoi or shonen ai manga. The only example I can find is Kuroneko Guardian. The boy is smaller an effeminate while the girl is tall and strong.

Also I would prefer it if this wasn't confused with harem or ecchi manga where the boy is attacked by a bunch of girls who for some reason love him or need to have sex with him.