Her father is an exile from the divine realm, and her sister is a chuunibyou with the ability to control ice and fire. However, Sanzenin Ryuzaki, who grew up in such a family environment that was completely unrelated to ordinary people, unexpectedly became an ordinary person. After his elder sister's plan to destroy the world failed, he followed his escaped sister to Ikebukuro, Japan. Since then, his life has changed drastically. The girl with unknown identity is a schoolmate, the leader of the red group is a teacher, the school chairman is a paranoid and a mecha master, the tsundere and the yandere twin sisters are the disciplinary committee, the boss and the mysterious exposed woman are neighbors, and finally they have a vigorous love affair with a rotten girl with dark attributes? ! At the same time, the DS team known as the "Terminator of Japanese Terror" and Japan's strongest prosecutor vow to catch them all. With the incredible city of Ikebukuro as the stage, their extraordinary youthful daily life is about to begin!