A young man silently watches Rinko, a housewife riding her mamachari bicycle, from afar. He once tampered with her bike and now secretly sniffs the scent of her saddle while indulging in fantasies. The next day, after finishing her grocery shopping at the supermarket, Rinko finds a group of delinquents surrounding her bicycle. They steal her saddle, leaving her helpless and forced to beg for its return. But when the saddle is finally returned, something terrifying has been attached to it...