In her youth, Ai grew up in rural Akita Prefecture under the care of her mother. However, when she was just three years old, her mother abandoned them without any apparent reason. Despite their modest living conditions, Ai found solace in spending time with her father until he tragically passed away due to an accident. Left all alone once again, Ai was taken in by her uncle Kenzo, who lived in Tokyo. At first, life seemed better than ever; Uncle Kenzo showered her with love and affection. But things took a dark turn...