Masatora Akutsu has just transferred into class in Japan from a long way away - all the way from Hell, to be exact. Akutsu is a demon who's come to Earth to find someone who can motivate the forces of Hell to fight back against the invading Heavenly army. He immediately sets his sights on one of his classmates, the kind and beautiful Lily Amane, but ends up in way over his head when it turns out Lily has some secrets of her own!

自我が目覚めたリーリヤは純真無垢――ではなく性的なことに興味深々!? 自我が目覚めたばかりのリリーの素体、リーリヤ。 ひとりで学校に忍び込んでは珍事件を起こし、間違った（？）性の知識を学んでいき――!? 性にまつわる知識を求めて人外女子とのじゃロリ天使が奔走するドタバタエロコメディ！