Ryo, whose husband is away on a long business trip, is releasing her pent-up sexual desire through exercise. One day, her son's friend Kosuke comes to visit, and she is captivated by the young, strong cock she happens to see... Unable to resist, she makes advances on him. At first, Ryo is pleased after coming multiple times, but Kosuke has an insatiable penis that doesn't stop after just one or two times. The intense thrusts continue without end, with no telling when they'll ever reach their end, and Ryo's body soon begins to scream in pain as she experiences repeated orgasms every day...