Jinbo-cho in the June 1922 rainy season Tamamori, who came to Tokyo from Aizu, is a roninsei (masterless samurai) who seeks to pass the Imperial University. However, due to his unfathomable fantasies and sloppy character, he is confined to his boarding house in just two years. Tamamori, who came to live in Umebachdo, an old book store with a certain relationship, was enjoying the grace period of being a roninsei while depending on his best friends in the same village. Under such circumstances, his best friends who he relied on committed suicide one after another and died unnaturally. Tamamori, who realized that he had been repeating the three rainy days for some reason, made efforts in Jinbo-cho to rescue them. What is real and what is a hallucination? A pop occult Taisho mystery that follows the mystery of the death of a friend.