A beautiful mother, Miyabi, lives with her son, Satoshi. Although they live happily every day, she feels lonely as she has not been able to see her husband, who has been away overseas for long periods of time. One day, when her son's best friend, Yu, who she has known for a long time, comes to the house to observe the stars, he suddenly confesses his love to her and kisses her. Miyabi feels her heart pounding uncontrollably, despite her own will. After that, Yu forces her to kiss him again, and Miyabi becomes addicted to the pleasure...