Goi is a tsukumogami, a spirit formed when an object gains sentience after a century of existence. He manifests specifically as a kiseru, a traditional Japanese smoking pipe. Goi resides among the inventory at the Izumo-ya lending shop, located in Edo's Fukagawa district. This shop lends everyday items to residents, and some, like Goi, are tsukumogami capable of communication and interaction.

He shares Izumo-ya with fellow tsukumogami, including Notetsu (a bat-shaped netsuke), Tsukuyomi (a full moon kakemono), Ohime (a princess doll), and Usagi (a comb). The shop is run by siblings Okō and Seiji, both of whom can perceive and communicate with tsukumogami. Goi, like the others, occasionally assists the siblings in their endeavors, which involve solving mysteries and addressing customer challenges.

Tsukumogami lore dictates that objects acquire a spirit after roughly one hundred years, gaining self-awareness and the ability to interact with the human world. They are not inherently dangerous and often exhibit personalities reflecting their former use or abandonment. While Goi's specific personality traits, dialogue, or individual actions remain unspecified, his existence as a kiseru tsukumogami integrates him into the communal dynamic of the lending shop and its resident spirits.

Goi's background story, specific development across the narrative, and any appearances in expanded media like the sequel novel *Tsukumogami, Asobō yo* are undocumented. His role is defined by his nature as a kiseru tsukumogami within Izumo-ya.