When Takeshi, a son, finds out that his beloved mother Yu is having trouble with her sexual relations at night, he decides to "satisfy her in place of my father." Yu rejects Takeshi's advances, but contrary to her feelings, her frustrated body is yearning for a hard penis. Yu's reason breaks down as he continues to piston her endlessly, no matter how many times she cums. She opens the door to the ultimate orgasm that goes beyond climax...