Ore to Kimitachi no Dungeon Sensou

Ore to Kimitachi no Dungeon Sensou summary:

In the year 2045 A.D., Earth was invaded by four different worlds.
In order to defend the Earth, it is necessary to conquer the dungeons connected to each of the other worlds.
Each country selects "explorers" to take on this responsibility, and Gunma, an ordinary man selected in Japan, is suddenly thrown into the front line of the attack!
While scared and over-equipped, he activates his "listening ear" and "searching for enemies" skills, and encounters the most beautiful girl of all mankind!
While being pushed around by the girl who is too strong for her own good, but has a tofu mentality, he is going through the dungeon attack at breakneck speed. ......?
This is an unprecedented dungeon fantasy that loosely knocks down everything!