When his beloved mother, Yu, learns that he is having trouble with his night life, his son, Takeshi, decides, "I will satisfy my mother instead of my father." Yu refuses the approaching Takeshi, but contrary to her feelings, her frustrated body has been waiting for a hard cock. Yu's reason collapses in the infinite piston that does not end no matter how many times it gets caught. She opens the door to the ultimate orgasm beyond the climax ...