The protagonist, Yang Jun, is transmigrated into a lowly mushroom man leader in an underground dungeon, a weak being bullied by all.
These dungeons are frequented by “players,” not humans but other species such as snails, earthworms, bacteria, idealistic birdfolk, victory-obsessed drake lizards, and brutal demonkind.
To survive and one day see the surface again, Yang Jun cultivates mushroom soldiers and leads his people in a rising conquest.