Ai Kishimoto, Yukari Miyazawa and Akane Kishimoto are sisters. The sisters live apart in Kanazawa, Toyama and Tokyo, but they gather together to attend their grandmother's funeral. There, they learn about their mother whom they know as deceased. While seeking out the the truth about their mother, the sisters face their own problems, but take a courageous step forward.
As a child, Manami attended her father Takuma's boxing matches and marveled at the scarlet shoes he wore. Unfortunately, he and his wife died in a terrible accident while he was preparing for the long-awaited championship. Now a single mother of a daughter she adores, Emi, Manami has decided to follow her father's footsteps and is back in the ring after her husband died of a long illness. However, her mind and body are not there and she is humiliated. Sinking into poverty, barely able to feed Emi and losing every job she has, her mother-in-law gains custody of her daughter. Overwhelmed by grief and anger, unable to catch her breath, she falls to her lowest point. However, her coach comes to pick her up from the Fukuoka Red Light and promises to make a champion of her so she can reconnect with Emi.
