After a night of drunken revelry, 19-year-old Kouta Satou decides to relieve himself near a seemingly secluded temple. Meanwhile, an angel is attempting to seal the queen of the underworld into a holy ball with his bow. Unfortunately, he misfires, trapping her instead inside of Kouta's unwitting balls. The angel departs, leaving Kouta a dire warning: if he fails to resist ejaculating before the end of the month, the queen will be released and mark the end of the world.

For the lustful Kouta, such a commitment is easier said than done; on top of using any means necessary to resist temptation, he must also guard himself from advances made by Elyse, an incompetent horned tsundere loli who has been sent up to Earth to release the Queen at all costs. The only way to do so is to make Kohta ejaculate, and Elyse only has 30 days to do it.
The battle for mankind has begun, in Kohta's pants.