Kaoru Kunou, once a legendary “Dungeon Maniac,” has now fallen to the very bottom rung of explorers for certain reasons. Worn out by reality but still chasing the tail end of his dreams and youth, one day he happens to save Shion—an S-rank dungeon streamer gal—during a moment of crisis. To his surprise, the bright and irresistibly charming Shion instantly falls for him at first sight. Though bewildered by her relentless affection, Kaoru slowly finds himself healed—and drawn to her. Forming a temporary mentor-apprentice duo, the two of them eventually challenge the deep levels of a dungeon tied to Kaoru’s past...!?