The constant rain in Tokyo is disrupting the daily lives of its inhabitants. Hodaka Morishima, a struggling high school student, finds himself working at a small publishing company to make ends meet. Meanwhile, Hina Amano is also searching for a job to provide for herself and her younger brother. Their fates become entwined when Hodaka tries to rescue Hina from some shady characters and they end up running away together. Hodaka soon discovers that Hina possesses an incredible power - she can summon the sun when she prays for it. Knowing the potential of her ability amidst Tokyo's unusual weather, Hodaka suggests that Hina become a "sunshine girl" to help clear the sky for those in need. Initially, things begin to look up for the pair, but it soon becomes clear that every power comes with a price.