Musashi Shinonome, grandson of the former owner, inherits the long-closed pachinko parlor "Shitamachi God Heaven" (or "Downtown Godhaven"). Upon coming of age, he reopens the business. During an initial inspection of the premises, he discovers a young woman named Hanabi living inside the building; she turns out to be a vintage pachislot machine transformed into humanoid form.

As the new manager, Musashi runs the parlor's operations, overseeing a staff that includes Hanabi and several other anthropomorphic pachislot girls, each possessing distinct personalities and abilities. His duties involve preparing the parlor for its grand reopening and navigating the daily antics of his unusual employees. He often serves as the "tsukkomi" (straight man) in comedic exchanges, reacting to Hanabi and her friends' chaotic behavior as they playfully mock or challenge him.

Musashi's background is defined by his family connection to the parlor and his pragmatic approach to managing the unexpected situation of sentient pachislot machines. His consistent role focuses on maintaining order within the absurd supernatural workplace environment, with no significant evolution in his personal circumstances or relationships detailed beyond this core premise.