To conquer the dungeons that suddenly appeared on Earth a hundred years ago, students now attend academies to train as adventurers. Among them are two rivals: Kuroto Sainokami, the academy's strongest delinquent, and Yukihime Mononobe, an elite noble honor student. One day, the two of them find themselves trapped in a dungeon, inside a room that they can't escape unless they're holding hands!? Will these sworn rivals be able to clear this high-difficulty mission and conquer the dungeon...!?

(Source: Kadokawa, translated)