When Shinji reunites with his college friend Yuji, Yuji admits that sex with his wife has recently dropped to barely once a week. Even so, he boasts about Marina, his beautiful and charming wife who is always eager in bed, and tells Shinji how wonderful marriage is. Frustrated and consumed by lust, Shinji secretly visits Marina and forces himself on her. She resists but still climaxes under his relentless stamina. Shinji then keeps coming inside her four times a day, five days a week, for a total of 20 creampies, until Marina can no longer be satisfied by her husband...