When the son of an American man and a Japanese women is killed in a car crash, the man transforms into a rageful metallic being thirsty of blood and vengance.

This is a story of a young woman and her coming of age in Japan. In the winter before her college graduation, Michiru received a letter from a girl. Apparently, they are sisters who shared the same father. The letter explained their father who has left Michiru from her birth. Even though she had never cared about him, the fact about his existence spread within her.