Kenji Saito

Heavens Library & Crimson Lord brings back Arata, Lilith and the rest of the Trinity Seven to face off against the greatest enemy in the history of the Trinity Seven; Lilith’s own father, who is revealed to be the strongest Demon Lord who challenges Arata who is now a Demon Lord candidate.

Arata inadvertently touches "Hermes Apocrypha," Lilith's Grimoire. Suddenly, he is enveloped by a bright white light, and a girl appears before him. She calls herself Lilim, and treats both Arata and Lilith as her parents. At the same time she appears, something changes in the world. The forbidden Eternal Library awakens.

In this "romantic comedy but sometime serious magical school story," life as Arata Kasuga knows it is wiped out by a bizarre incident known as "Collapse Phenomenon," which causes worldwide destruction and takes his cousin Hijiri Kasuga to the next world. To resolve the "Collapse Phenomenon" and bring back Hijiri, Arata enrolls in the Royal Biblia Academy. Waiting in the school are seven beautiful female magic users — the Trinity Seven.