(on Wikipedia)
https://www.imdb.com/title/tt21209876/
https://sololeveling.com/
https://sololeveling-anime.net/
Mysterious gates bring monsters into the world, but people develop superpowers and one previously-worthless combatant becomes incredible.
Pretty good so far.
- Original title: Ore dake Level Up na Ken
-
The origin is Korean, but this is a Japanese endeavour.