Beelzebub S00 E09 Charge!! Beelzebub and the Shinsengumi 2

Violent delinquent Oga encounters a baby one day, which crawls onto his back and immediately forms an attachment to him. Though he doesn't know it yet, this baby is named Kaiser de Emperana Beelzebub IV, or "Baby Beel" for short—the son of the Demon Lord!