Saburo Tabuchi, alias Metroyellow, is one of thirteen God candidates vying to become the next God. He possesses short dark hair, wears glasses, and favors neat attire. Saburo attended cram school alongside Shogo Hatakeyama, both aiming for humanities universities. After failing their entrance exams—Saburo once, Shogo three times—they abandoned hope and planned a joint suicide using Saburo's pills. Shogo desired a final day of fun before dying but became physically ill and questioned seeking enjoyment. Saburo could not understand this perspective, believing their lives were already over. Their guardian angels, Egura (Saburo's) and Emaka (Shogo's), then appeared, restoring their hope. They pledged mutual support in the competition, promising happiness to the other if one became God.

Responding to Metropoliman's public call for candidates at Jinbo Stadium, Saburo and Shogo arrived disguised as "Metroyellow" and "Metroblue," challenging the real Metropoliman. This played into Metropoliman's trap, which utilized manipulated human decoys. Saburo and Shogo revealed their true identities as God candidates, intending a direct confrontation. Metropoliman quickly subdued them: he shot and killed Shogo with a White Arrow. Saburo was restrained and handcuffed to fellow candidate Chiyo Nakayama. Metropoliman used Saburo as a hostage, threatening his death unless other candidates revealed themselves. When no one complied, Metropoliman executed Saburo with a White Arrow. Saburo's story culminated in his death at the stadium, followed by his angel Egura departing for the Celestial Realm.