One day, the protagonist is informed that a villager has gone missing so
heads to a mysterious ruin. However, he falls for the trap at the deepest floor.
Soon after he realizes that he has fallen to an underground cave.
There are a lot of monster girls that sexually assault humans!
He finds a note of somebody, telling him that if he cummed in intercourse
with any monster girls, he will be paralyzed and made into their slave.
To get out of this underground dungeon, he has to overcome many temptations!