Maou ga Moto no Sekai ni Kaerenai no wa Ore no xx ga Tarinai Sei | 魔王が元の世界に帰れないのは、俺の××が足りないせい？

[Thus, your semen is accepted] It was said to the protagonist by the girl who showed up suddenly, a certain midafternoon.

Spring vacation of that year... University student's protagonist doesn't have her, especially there is not a plans either, Idly was spent alone. That sort of case, it is bored and finds the method to which the demon is summoned by the Net Surfin, it is tested. Do not you succeed surely...? When the protagonist thinks so, the girl of the alone show up from the magic square drawn on the floor?

The woman who introduces herself herself as the king demon, the thing that has been summoned on the way from be defeated because of the struggle for supremacy of Hell and run away is reported. To get a magical power necessary to knock down a enemy in the original world, king demon who requests cooperation from protagonist. The proposal... mean that if you refuse it is killed, mean to him who accepted a threat unwillingly, it was a speech that she had reported at the time ahead. Protagonist that can do nothing but be naturally agreed.

Then immediately... though energy it is a king demon who tries to accept, however it thinks suddenly. That method is unknown to tell you the truth. To her puzzled how it is necessary to do, then the protagonist returned i teach. The virgin! Suppressing sexual desire any more puzzled of the mind, he lifts the king demon in one's arms.

The protagonist really gives the king demon energy, do it be able to do to former world?