Hariyama-san, Center of the World

Hariyama-san, Center of the World is a series of connected short stories by Narita Ryohgo, the author of Durarara!! and Baccano!. They’re basically strange or supernatural events that are seemingly unrelated, except that every one of them involves the title character, Shinkichi Hariyama, as a minor character in some capacity. The last story in each volume ties all the previous stories together. It doesn’t take place in the Naritaverse (consisting of Durarara!!, Baccano!, Vamp!, and Etsusa Bridge)