Aya Masuo, a milf who lost her husband and lives alone with her son, begins to rediscover her sense of self amid daily life. One day, she is approached by her son's friend, Shimizu, who starts calling her "mom," gradually drawing her into an intimate relationship. As their bond deepens, they cross forbidden boundaries. Aya's long-dormant desires awaken, and yielding to Shimizu's advances, she descends into a world driven by intense, uncontrollable impulses.