>>156366My Balls (Oretama in Japanese) by Shigemitsu Harada: The fate of the world rests on one man's shoulders. Or, to put it more precisely, it rests in his right testicle.
Emmaniel, the Queen of Terror, is a demon on her way to destroy the world. Then, in an accident involving an angel, a Soul Jar and a stream of urine, she is sealed away inside the right testicle of perennial loser (and virgin) Satou Kouta. The angel informs him that if she remains sealed for the entire month, the world will avoid destruction. The only way for Kouta to keep her sealed is to not ejaculate for one month, or she'll escape. Thus Kouta must resist temptation for a full month, lest the world be destroyed.
