When Daisuke sees his mother-in-law, Shiho, sweating and doing household chores, she is fascinated by the luster of the sweat that flows from her abundant body. Since then, Daisuke has suppressed his feelings and concealed the inferiority he had for Shiho. However, one day, Daisuke witnesses the flirtation scene of Shiho. Anger for betraying his father became a detonator, and the inferiority that Daisuke had finally suppressed exploded. It attacks Shiho like a beast ...