A beautiful mother, Miyabi, lives with her son, Satoshi. Although her days are happy, she feels lonely because she has not been able to see her husband who has been away for a long time due to overseas assignments. One day, when his son's best friend, Yu, who was an old acquaintance, visited his house to observe the stars, Yu suddenly confessed to him and kissed him. Miyabi felt her heart pounding in her chest, despite her will. After that, Miyabi is forced to kiss Yuu again, and she becomes addicted to the pleasure.