Yuu Nanase is a third-year student in class B at Akenomiya High School, located in Hiroshima, Hiroshima Prefecture. She stands 160 cm tall with distinctive red hair and measurements of 85-56-85 cm (bust-waist-hips).

Her interests center around traveling and stargazing, reflected in her favorite school subjects: geography and astronomy. While exploring during her travels, Yuu encounters a girl who has lost faith in love. Motivated by this meeting, Yuu sets out to convince the girl that true love does indeed exist.