Manga help remmeber involving dungeons in the real world

The manga shows that dungeons appear in the real world

Mc enters into a dungeon young and after a year pr so he is strong (iirc)

There is an elite team that clears a dungeon thanks to the help of mc, they offer mc a position to which he declines, he tells them to take the credit for completing the dungeon and they do.

After this arc, i beleive the second arc introduces a gyaru/gal

Im sorry if this is vague, i legit cannot rmemebr anything else but it was good (im certain it is not "the worlds fastest level up")