You're referring to the anime "Beelzebub"!
One day, while on his way home from school, Oga encounters a demon named Beelzebub, who is the son of the demon king, Satan. Beelzebub has been sent to Earth to be reared by a human, as his father wants him to learn about human ways. beelzebub anime dub episode 1
During their encounter, Oga is possessed by Beelzebub's soul, and the demon's powers are unleashed. As a result, Oga becomes the unlikely host and caretaker of Beelzebub. You're referring to the anime "Beelzebub"