Taiyo Asano is a super shy high school student and the only person he can talk to is his childhood friend, Mutsumi Yozakura. It turns out that Mutsumi is the daughter of the ultimate spy family! Even worse, Mutsumi is being harassed by her overprotective, nightmare of a brother, Kyoichiro. What drastic steps will Taiyo have to take to save Mutsumi?! A spy family comedy - the mission begins!

The manga centers on Poro, a demon from the underworld who comes to the human world.

Werewolves, vampires, dragons, and all sorts of other mythological beings are real, and they live hidden among us. But in order to stay hidden, they need special doctors who can treat them without having to worry about their true natures being revealed. Toteku Tatsumaki is one such doctor, a young yet brilliant human boy who has genetically altered his own body to better be of service to the supernatural community.

Genjui Toteku won the 10th Weekly Shounen Jump's Golden Future Cup competition.