Dai Shibaura, a bar owner and former pachislo machine designer, guides the protagonist into the clandestine world of underground pachislo, discerning their uncanny knack for halting moving objects with pinpoint timing. He ushers them into the Slosseum—a secret arena hosting high-stakes pachislo duels—leveraging their talent to challenge its elite competitors.

Years prior, Shibaura co-created the Yozakura #1 pachislo machine with Kojirou Shinbashi, the protagonist’s estranged father. The machine’s legacy intertwines with a tragic event linked to Ryo Daiba’s fallen comrade, a history Shibaura safeguards through photographs exposing his ties to Shinbashi and the protagonist’s family.

By bridging past and present, Shibaura propels the protagonist toward confronting Daiba, the Slosseum’s reigning champion, while unraveling buried family wounds. His maneuvers aim to hone the protagonist’s skills and quietly reconcile lingering strife from Shinbashi’s abandonment, threading personal reckoning into the clash of pachislo mastery.