Tatsumi Oga, a delinquent student at the worst high school in Japan, arrives at school with a small baby who emits massive shocks of electricity whenever it cries. Oga claims he found after splitting open a strange man who came floating along the river, though his friend Takayuki Furuichi doesn't quite believe. Whilst at Takayuki's house, they are both approached by a demon woman named Hildegarde who claims the baby, known as Kaiser de Emperana Beelzebub IV, is the son of Devil King who was sent to Earth to find a human to raise him so he could destroy humanity.

Himekawa introduces himself and tells everyone how he makes his "super cool" pompadour: by hardening it with a hair gel called Pomade. Furuichi ignores him and mentions a man showing up. Himekawa thinks he's referring to the Legendary Warrior, Super Pompadour. Oga asks who that is. After Himekawa introduces the two-part episode, Oga becomes surprised that the Great Demon Lord is showing up, while Himekawa ignores him and worries about his lost pompadour.

It begins with a bunch of Ishiyama delinquents crying and mourning over the loss of Oga and Baby Beel. Their tears stop short by the river when Alaindelon cruises like a speedboat and Oga and Beel pop out of the man.

At Oga's house, Hilda explains that the Great Demon Lord has no interest in destroying humanity which means the goal of raising Beel to destroy all humanity is no more. Beel and his gang will have to go home, and mass hysteria follows.

Will Oga, Beel, and the gang part ways forever?