Subaru Kashino travels to a high school in the countryside for a sports training camp where he meets Kei Natsume, a library committee member. Subaru expectedly finds himself curious about the boy in the library. Then one night Subaru has a sensual dream about his new friend. When it's time to return to Tokyo, Natsume suggests instead of calling each other to write letters. Confused, but intrigued, Subaru decides to start writing to Natsume.