After several peaceful years of marriage, a junior colleague named Yamada boasts that married women in their third to fifth year are the easiest to seduce. Certain that Kaho would never betray him, her husband argues back, but their stale sex life makes him susceptible to Yamada’s challenge. Days later, he invites Yamada home and invents an excuse to leave the two alone for three hours—only to lose his wife after Yamada pounds her without pulling out and gives her 16 creampies.