Aomi Hina

The lowest level of the dungeon sprawling beneath Shibuya... an uncharted realm where humanity had never before set foot. Despite being a dungeon, it features forests, lakes, and a cycle of day and night. Minato Shiraki, a university student and adventurer who had been enjoying a laid-back lifestyle in a log cabin there, rescues Rei Minami, a beautiful dungeon streamer who had wandered into the perilous "Nether Layer." Having shot to fame as the man who conquered the Nether Layer, Minato forms a party with Rei and finds himself vying for supremacy against adventurers from both Japan and abroad.