In a city of the dead, long since ruined and far from human civilization, lives a single human child. His name is Will, and he's being raised by three undead: the hearty skeletal warrior, Blood; the graceful mummified priestess, Mary; and the crotchety spectral sorcerer, Gus. The three pour love into the boy, and teach him all they know. But one day, Will starts to wonder: "Who am I?" Will must unravel the mysteries of this faraway dead man's land, and unearth the secret pasts of the undead. He must learn the love and mercy of the good gods, and the bigotry and madness of the bad. And when he knows it all, the boy will take his first step on the path to becoming a Paladin. (Source: J-Novel Club)

Self-professed "home security guard" Mahiro Oyama has not left his home in years, secluding himself in his room playing erotic visual novels. This depraved lifestyle causes his prodigious sister, Mihari, to worry about his well-being. In hopes of solving this problem, she devises a plan to rehabilitate him back to normalcy. The first part of Mihari's plan is to concoct a medicine that changes her brother's biological constitution into a bona fide female, much to Mahiro's vehement dismay. Stuck in this predicament, Mahiro has no choice but to live out his life as a cute girl until the effect wears off—if it ever does.

As far as it goes, many boys, especially in their teenage years, want to have a girlfriend. Keiki Kiryuu is no exception. One eventful afternoon, his days of yearning for a lover seem to come to an end when he receives a love letter from an anonymous sender—along with a pair of white panties. To determine the identity of his secret admirer, referred to as Cinderella, he proceeds to investigate several possible candidates including his senior Sayuki Tokihara, his underclassman Yuika Koga, and his classmate Mao Nanjou. However, as Keiki seeks to uncover who this mystery girl might be, he comes to know about the perverted fetishes hidden behind each candidate's innocent exteriors... [Written by MAL Rewrite]

An unaired episode of Shinmai Maou no Testament, bundled with the eighth light novel volume.