After the Demon King was defeated, a mysterious "Hidden Dungeon" suddenly appeared in a remote town — a place swarming with unimaginable monsters and housing unbelievable treasures! Yui, a newlywed eager to conquer the dungeon, harbors a secret...!? A Level 99 martial artist who once saved the world has now "reclassed" to Level 1 as a housewife, but is forced to challenge the deadliest dungeon yet! Follow the adventures of this unstoppable martial artist in her newlywed dungeon-conquering diary!