For Yumi, who raised her son alone, her son was an irreplaceable treasure. That's why she never let her son see her suffering. Perhaps knowing this, her son supported Yumi as much as he could. However, Yumi had a fiance whom she trusted more than anyone else. And it was her son's best friend... When he caressed her passionately, her mind, which should have been filled with thoughts of her son, was gradually filled with the presence of her beloved fiance...