The noble William possesses a rare kind of intelligence. The school he attends and his family background both draw much attention. However, one day, his family loses money after his uncle's business fails. Worrying about how this would affect his school's reputation, he returns home to help the family butler search for things to sell. What they found was an underground room that had been used by William's ancestors. The room contains a magical seal, with which William unintentionally summons a demon. The demon, Dantalion tells William that has the ability to choose the king of the demon world! Naturally, the candidates for king will come after William...who will become king in the end?!
(Source: Hyper Parfait)

A timid boy named Zao Ci, which was accepted by Mateliya, a Demon as her "number 2". He was always called an idiot by Mateliya. He is so weak that he could not even pull the trigger of his gun. But, who actually knows that he had a special power within him, which only Mateliya can control. This begins the adventure of the contract of the boy and his master to save others.

Luca Athrason has been sentenced with 500 years of imprisonment – such is the price to pay for his sins. The only way for him to shorten his sentence is to accomplish his missions as the Church’s vanguard or as some might call it... The Church's Dog!

Polyphonica is a world where spirits and people co-exist.
Snow (スノウ) serves the dantists of the Granado family, however their "commandia", which gives the spirits strength, has been waning in each generation.
What does fate have in store for her?

Japan, Year 2X65, Tokyo. As the population continues drop due to a mysterious disease, through a certain incident, the fates of two young men, the orphan Noel, and Rikka, the heir of a distinguished Mafia family, will cross... A thriller, depicting the tale of their Bond of Blood...