Fresh out of college, Musashi Shinonome inherits the Shitamachi God Heaven pachinko hall from his late grandfather and decides to pay it a visit. Inside, he encounters a peculiar sight: a girl named Hanabi Hana Ariake, claiming to be a perfected pachislot machine transformed into a human. Demonstrating her fireworks-shooting ability, she surprises Musashi. As days pass, Musashi gets acquainted with Ariake's two human pachislot machine sisters— the lively Versus Ikusa Takanawa and the affectionate Thunder Rai Nihonbashi. Together, they strive to ensure the successful reopening of Shitamachi God Heaven through their collaborative efforts.