After inheriting the Shitamachi God Heaven pachinko hall from his grandfather, Musashi Shinonome, a recent college graduate, pays a visit to the place. While exploring, he discovers a girl named Hanabi Hana Ariake, sound asleep on a futon. When she wakes up, she introduces herself as a pachislot machine who has amazingly transformed into a human form. To showcase her abilities, she creates fireworks that explode out of her body. As time passes, Musashi meets Ariake's other two human pachislot sisters, Versus Ikusa Takanawa who is full of life, and Thunder Rai Nihonbashi who is devoted. The team of four works hard to prepare for the grand reopening of Shitamachi God Heaven, hoping for a successful result.