She suffered from a deadly illness when she was a young girl. Her twin sister Sawa fed Towa the blood of a mermaid. The blood made her better, but unfortunately, she developed a deformed arm, similar of a Lost Soul's and her hair turned pure white. She didn't age on the outside, but her insides were the same. When Towa's father learned of what Sawa did to her, Towa locked up in a cell underneath the house and was never allowed to come out. Sawa had a life of her own; getting married and having a child of her own while Towa lived alone in the world except for her fiancée, Dr. Shiina. Her deformed arm caused her terrible pain. She asks Dr. Shiina to dissect the arms of dead girls and re-attach them onto her. But every arm has turned deformed and the pain gets worse. She is about to lose hope until Mana is killed in a car accident. Dr. Shiina is about to cut off Mana's arm, but when Mana came back to life, she comes up with a plan. She will replace her body into Mana's unless Sawa tells her where the mermaid mound is. Towa had shown a small love interest for Mana, but it is unknown if she loved her for the fact that she has an immortal body or the anything else. Towa found the mermaid and wants to give the flesh to Sawa to fulfill her revenge, but Sawa dies of a cardiac arrest, leaving her with nothing to show her life. In the end, Towa joins her sister in death.