Ever since his boyhood experience with a burglar in his house, Mamoru has made security a major theme in his life. Joining a security firm, gaining early promotion and his engagement to the daughter of the company director has brought him a very happy point in his life. But on the way to a business meeting, he meets Misa, a woman dressed in mourning, who seems to bear a deep grudge against him although he has no idea who she is. From that moment on, Mamoru’s life begins to collapse around him.