Due to her husband's frequent business trips, married woman Ayumi lives alone with her son and secretly copes with loneliness and sexual frustration by masturbating in the bathroom every night. Her son's friend notices her habit and begins aggressively pursuing her, eventually forcing her into intimacy. Her body gradually becomes highly sensitive, responding intensely as she is repeatedly teased and pleasured, leading to a complete mental and physical release. This shocking story captures her growing obsession with the overwhelming pleasure.