Dalk Gaiden

Our hero is the Love God, "Martis," who also appeared in the previous title. He was turned into a regular person because he disobeyed the Master God, Furad. He ends up searching inside the body of the giant god Varuga with 7 maids in order to subdue the Demon God, Port Nunu. This parasitic demon is running rampant around in Varuga's body.
Varuga's body is a labyrinth, which consists of a giant dungeon with many floors. Martis and the maids advance into the dungeon as they beat small monsters on their way to defeat Port Nunu, who is hiding in the deepest area of the dungeon.

[From Gamelex]