Beautiful mother Miyabi lives with her son Satoshi. Although they have happy days, she feels lonely because her husband has been away on overseas assignment for a long time and they haven't seen each other. One day, Satoshi's childhood friend Yuu visits their home for stargazing and suddenly confesses his feelings to Miyabi and kisses her. Despite herself, Miyabi feels her heart pounding uncontrollably. Later, when Yuu presses her again, Miyabi accepts another kiss and finds herself getting addicted to the pleasure…
