Shirou, a third-year junior high student, spends his days with school friends in Minami Shimabara, the Nagasaki city said to be where the Shimabara Rebellion began in the early Edo period. One summer, his older childhood friend Akane comes back from Tokyo, and the two wander the city with Tokiya, another old friend, amid nostalgia and more tangled emotions. Then a mysterious little creature called Goron shows up in front of them, and its arrival sets major events in motion in the city once again. The four-episode drama mixes mystery with the supernatural.