I Picked Up The Demon King (魔王ひろいました, Maō hiroimashita)
Oga tells Furuichi how he pick up Beelzebub; Hilda appears and explains that Beelzebub is the Demon Lord's child and that Oga has to raise him to destroy mankind. When Oga declines, Hilda decides to kill him. In the end, Oga saves Beelzebub from a collapsing tower which earns him the trust of Hilda and Beelzebub.
Later on, Oga learns the challenges of raising Beelzebub; when he cannot bear the burden of it, he tries to pass the baby to a stronger human such as Kanzaki. However, Kanzaki is not suitable. Another challenge that Oga face is when Beelzebub causes a flood by urinating it. The day ends when Hilda has Oga hold Beelzebub to empty his bladder in the ocean after Hilda notices Oga is improving as a parent. When Oga notices the Zebul mark on his hand, Hilda explains he has the official contract as Beelzebub's parent. Oga decides not to fight which results in Hilda and Furuichi's kidnapping by Kanzaki.
Chapter 1 - I Picked up the Demon King (魔王ひろいました, Maō hiroimashita)
Chapter 2 - I Became a Gang Leader with a Child (子連れ番長はじめました, Kozure banchō hajimemashita)
Chapter 3 - Damn Strong Evil Bastard (強くて凶悪でクソヤロー, Tsuyoku te kyōaku de kuso yarō)
Chapter 4 - FLY!!
Chapter 5 - Planned to Become the Mother (母親になったつもりで, Hahaoya ni natta tsumoride)