Katsu, portrayed by Mitsuko Baisho, is a 73-year-old woman known for her sharp tongue, which often lands her in trouble. Having raised her daughter on her own, Katsu never had the chance to live the life she truly desired. One day, she visits a photo studio to have her picture taken. Upon leaving, she discovers she has transformed into her 20-year-old self, played by Mikako Tabe. Embracing her youthful appearance, she ditches her grandmotherly attire for a more modern look and adopts the name Setsuko Otori. Seizing the opportunity, Katsu enters a singing competition at a local shopping area. Her performance captivates the audience, earning her the victory and bringing her closer to her long-held dream of becoming a singer.