沼る

ぬまるnumaru

godan verb · intransitive

1. to get hooked (on a video game, TV show, etc.)
2. to become addicted (to)
3. to become obsessed (with)
4. to be in a slump
5. to struggle to make progress
6. to get stuck (e.g. at a certain rank)

Study it in Yanamino