Rika, a single mother, has been raising her son Mamoru alone. Lately, she seems to be in a romantic relationship with a colleague from work, which Mamoru, who is overly attached to his mother, dislikes intensely. This feeling grew so strong that Mamoru started sneaking into Rika's bed at night... One day, Rika decided to bring her lover home. Mamoru left the room, visibly disgusted, but returned out of curiosity and found Rika entwined with her lover! Shocked by the lewd sight, Mamoru went back to Rika's bedroom while she was asleep...
