Tatara Tani is just your typical high school freshman. He gets average grades and has average athletic abilities. But here's something interesting: Tatara's childhood friends - twin sisters - go to the same school as him. The elder sister, Ranko, is outgoing, while the younger sister, Yuriko, is a famous idol. Even though they've been growing apart, Tatara has always had a soft spot for Yuriko. And then one day, she surprised him by asking him out on a date. From there, Tatara found himself in a secret relationship with both of the sisters!