A sweet and dangerous fantasy about, a lonely person living alone in the whole world, as a bride-to-be! One day, Hana Kuzuno is hit by a black car and taken to the mansion of the "Onikan-gumi," a group of ghosts and demons. Hana is suspected of stealing her grandmother's treasure, the "Gyokuji," which is a counterpart to her grandmother's treasure, the Suisho, a memento of her grandmother. Hana is threatened with death if she does not find the Gyokuji, and is forced to live in the mansion. Furthermore, the clan leader declares that he will make Hana the bride of the next clan leader to prevent her from escaping... The dangerous and exciting life of a gangster begins, as he is pursued by Shiki, the most powerful member of the clan, and Byakuya, the young leader and a candidate for the next head of the clan.

Rika lived alone in her apartment. When she accidentally punched a hole in the wall, she found her strict, iron-masked teacher Kurogane-sensei on the other side! To keep quiet about all the personal "dark side" things she overheard from his apartment, Rika demanded extra tutoring from Kurogane-san! (Source: LaLa, translated)