終末のハーレム ファンタジア学園 [Shuumatsu no Harem - Fantasia Gakuen] #1

This is the first collected volume of the fantasy spin-off series set in the same universe as 'World's End Harem.' It follows a young man who awakens in a magical academy where he is one of the few males left, leading to a harem-centric adventure with fantasy elements. The volume collects the opening chapters of this side story from Shueisha's Young Jump imprint.