An 'apocalyptic' boy-meets-girl rom-com about high school boy Yutaka Kuromori and the beautiful, popular girl adored by everyone, Aru Hoshina. Yutaka might shyly deny it, insisting "we're not dating," but Aru is always clinging to him, and the two are seen as the talk-of-the-school couple.

But behind what looks like an ordinary boy–girl high school relationship lies a secret — one so ruinous and capricious that, if mishandled, it could bring about the end of the world.