Ainz Ooal Gown, the undead sorcerer formerly known as Momonga, has accepted his place in this new world. Though it bears similarities to his beloved virtual reality game Yggdrasil, it still holds many mysteries which he intends to uncover, by utilizing his power as ruler of the Great Tomb of Nazarick. However, ever since the disastrous brainwashing of one of his subordinates, Ainz has become wary of the impending dangers of the Slane Theocracy, as well as the possible existence of other former Yggdrasil players. Meanwhile, Albedo, Demiurge and the rest of Ainz's loyal guardians set out to prepare for the next step in their campaign: Nazarick's first war… Overlord II picks up immediately after its prequel, continuing the story of Ainz Ooal Gown, his eclectic army of human-hating guardians, and the many hapless humans affected by the Overlord's arrival. [Written by MAL Rewrite]

The final hour of the popular virtual reality game Yggdrasil has come. However, Momonga, a powerful wizard and master of the dark guild Ainz Ooal Gown, decides to spend his last few moments in the game as the servers begin to shut down. To his surprise, despite the clock having struck midnight, Momonga is still fully conscious as his character and, moreover, the non-player characters appear to have developed personalities of their own! Confronted with this abnormal situation, Momonga commands his loyal servants to help him investigate and take control of this new world, with the hopes of figuring out what has caused this development and if there may be others in the same predicament. [Written by MAL Rewrite]

Iwaki Tomonori is an average 15-year-old boy who likes older women. He happens to have a crush on his teacher, but soon thereafter, learns she has become engaged. He heads home brokenhearted, only to find a 12-year-old girl named Rizel at his home, who he learns the Japanese government has married him to against his will. Furthermore, he learns Rizel is no ordinary girl; she is a biochemically engineered human, and her creators (her "papa"s, as they are often referred to) promise to waive multiple bills of Iwaki's parents in exchange to be allowed to stay at their house, and thus Iwaki's life with Rizel begins.

Nurarihyon no Mago Recaps.