My Refrigerator Turned Into A Dungeon

One day, monster-infested dungeons suddenly appears around the world, causing people to shudder. In the midst of all this, an old two-door refrigerator in the apartment of a humble businessman is somehow also connected to the dungeon. The man who rents the room is bewildered, but attracted by its magical nature, he sets out to conquer the dungeon that only he knows about….