Mio Tokihara, a girl who became all alone in the world after successively losing her grandparents who raised her.

As she went about her daily life, vaguely worried about the future, she encountered a red-haired girl who had collapsed on the street.

However, Mio was attacked by the girl she had taken in, and her life was even targeted. Nevertheless, Mio extended a hand to the red-haired girl.

It was as if she had found her destined partner. Unaware that this was the gears of fate beginning to turn once again—