Today is the day of my only son, Takayuki, an important baseball game. "I have something I can't take away today," Yumi says, sending her husband and Takayuki out, and decides to stay home alone... The "important matter" is a secret meeting with her sex friend, Shinichi. What's more, she chose Yumi's home because she didn't want to waste even a second of time. Then the house chimes ring and Shinichi comes. The two of them start at this moment with "Unlimited FUCK"...