Beelzebub: Hirotta Akachan wa Daimaou!?

The story follows the "strongest juvenile delinquent", Oga Tatsumi, a first year in "Ishiyama High" the school for delinquents. One day while sleeping next to a river he sees a man floating down it, he pulls him to shore and the man splits in half revealing a baby boy. This boy is the son of the demon king and he has been chosen as the one to raise it with the baby's demon maid...