When Kasumi's husband dies in a car wreck, Ryuichi vows to watch over her and her unborn son. Over the next ten years, he gradually falls in love with Kasumi. Now 35-year-old, Kasumi has resisted loving another man for fear of reliving the pain of losing a loved one. She happens to meet Ryuichi's bad boy younger brother and finds herself physically attracted to him; but Ryuichi finally acts on his bottled-up feelings for Kasumi and asks her to marry him. Kasumi must decide if she can bring herself to fall in love with a responsible man like Ryuichi, or if she can be content with the purely physical relationship that his brother can provide.