She met Yuta years before World War II. Upon learning about Yuta's curse of immortality, she revealed a secret about mermaid ashes to him. She scattered the ashes all around a field of red flowers, causing them to bloom year-round, never wilting or dying with the seasons, even in winter. She named this place the "red valley." Soon, she and Yuta fell in love and began meeting privately in the red valley. Her fiancé, Eijiro, grew jealous of Yuta's affection for her but never believed she would betray him. He discovered her signal for meeting Yuta in the red valley and went there to confront her. When she arrived, Eijiro was shocked by her betrayal and strangled her to death.
As the years passed, Eijiro came to regret his actions and mourned what he had done to her. He learned about the mermaid ashes and found them. The ashes brought her back to life, but she became a shadow of her former self. When Yuta returned to her hometown with Mana, she planned to reunite with him, but Eijiro prevented it. Sometimes, she would fall into murderous trances due to her shadow form. Despite this, Eijiro remained deeply in love with her.
When Yuta and she finally reunited, she told him that she was having a nightmare. Yuta then remembered a village legend about a priestess who had come to the village carrying a jar of mermaid ashes. A man murdered the priestess, but the ashes entered her mouth, bringing her back to life as a shadow. She then retreated to the mountains, where she died. As the effect of the ashes wore off, she too was left to die once again in the red valley, her final resting place.
