Ryohei Abe, a high school sophomore, had a small habit he told no one about. On sunny days, he walks to school. Only on rainy days does he take the bus from the stop near his house. The reason was simple: he didn't want to get his precious reference books and notebooks wet for his dream of becoming a weather forecaster. However, Ryohei, whose outstanding grades made him stand out at school, was being bullied by some of his classmates and was losing his place there. Even so, he never gave up on his dream and spent every day studying. One rainy morning, Ryohei misses his bus and tries to head to school on foot out of necessity. Then, a woman—Guest—stands beside him and quietly says, "The bus just left, didn't it?" Guest says she takes the bus at this time to get to work only on rainy days. From then on, the two begin to exchange words for thirty minutes at the bus stop only on rainy mornings. Ryohei gradually begins to open up to Guest about his worries and dreams that he can't tell anyone at school, and before long, those thirty minutes become the most important time for him. The number of times he was late for school increased every time a rainy day came. Still, Ryohei continued to choose those thirty minutes. Meanwhile, although Guest listens kindly to Ryohei's stories, she tells almost nothing about herself. Not about anything other than her name, not about her family, not about her work—nothing.