With her husband away for work, Yurine lives alone with her withdrawn adult son. One day he brings home Saji, an adult friend from a single-parent family who claims to crave maternal affection. Yurine welcomes him warmly, but his warped fixation turns sexual and he exploits her kindness. He pounds her relentlessly with his rigid cock until she rediscovers long-forgotten pleasure, and the sensations deep inside gradually begin to overwhelm both her body and her loyalty.