Saburou serves within the Aoba yakuza group, bound by deep loyalty to Takao "Taka" Itou, whom he addresses as "aniki," and closely linked to Junichirou Uchida. His position in the organization remains fixed.

Amidst the chaos of the Great Kanto Earthquake, Saburou intervenes to shield Sara Uchida from attacking thugs. This act results in him receiving a fatal stab wound. With his final breath, Saburou informs Sara that Taka and Junichirou have already departed Tokyo. His death occurs during these events.