Tokyo is currently enduring rain showers that appear to endlessly disrupt the daily rhythm of its residents. Amidst this seemingly endless downpour arrives Hodaka Morishima, a runaway high school student who struggles to make ends meet, eventually landing a job at a small publisher. Meanwhile, the orphaned Hina Amano also strives to find work to support herself and her younger brother. Their paths cross when Hodaka attempts to rescue Hina from shady men, leading them to run away together. Subsequently, Hodaka discovers that Hina possesses a strange yet astounding power: the ability to summon the sun whenever she prays for it. Considering Tokyo's unusual weather, Hodaka sees the potential in this ability. He suggests that Hina become a "sunshine girl"—someone who will clear the sky for people when they need it most. Things begin to look up for them at first. However, it is common knowledge that power always comes with a hefty price...