Demon King of the Otherworld: The Protagonist's Mom Is My Maid!

Huang Yu transmigrates into the erotic action game Annihilate the Demons, where he inhabits the home of Nanako, a housewife in Tokyo's underworld, and becomes the Progenitor Vampire. By adding blood dolls and kin, he can gain immense power. In his previous life, he got into a fight with the protagonist, Fuma Kosaburo, over the school's most popular girl, Suzuki Anna, and took a beating. Huang Yu immediately sets a revenge plan in motion. From the start, he makes the popular idol Anna and her model older sister Riko, the beautiful sisters, his kin...

[After she pledged her loyalty, the protagonist's mother, Fuma Saija, actually became my secretary?]

[Being a Demon Slayer is too dangerous. If everyone becomes a vampire, we can't lose!]