Megami-ryou no Ryoubo-kun.

Nagumi Koushi is a 12-year-old boy who was abandoned by his broke father after their house caught on fire, leaving him to roam the streets penniless. Then one day, a girl named Minerva who finds him lying on the sidewalk takes him to a women’s college dormitory, one known for housing troublesome residents, and asks him to be their "Dormitory Mother...