Ousawa Akatsuki, trapped by summoning magic in the Otherworld realm of Alayzard, has finally been proclaimed a hero for defeating the Dark Lord Galious and a rogue hero for his independent and philandering ways. After choosing to return to his home world through the Otherworld Gate, he is inducted into BABEL University, a place where returnees can learn to develop and use the abilities gained in the Otherworlds for the good of humanity. However, Akatsuki has brought back a secret in the form of his beautiful long-lost sister Miu who is actually the daughter of the Dark Lord he defeated. Furthermore BABEL harbours secrets regarding the true purpose of training returnees, and Alayzard's troubles with the defeated Dark Cult and the secrets they harbour are far from over.