迷宮メトロ ～目覚めたら最強職だったのでシマリスを連れて新世界を歩く～ (Associated Names)

Abe Shuu wakes up in a strange place. Tokyo, a city that has been transformed by the “Metro Overflow” and the “Super Fungus Pollution” for the past 100 years. At the fiftieth underground floor of the Ootsuka Metro, a labyrinth of metro beasts. 「It’s like you were thrown into the last floor of the dungeon…