Yui overcame the predicament of single-mother families and raised her son Keita with one woman. Knowing or unknowingly of her Yui's hardships, Keita also grew up to be a solid man who loved her mother. One day, when Keita was at home, Yui and Keita's best friend Toru came home together. "Keita... Mother and Toru got married." Keita can't help but get angry at the two who seem so happy...
