— Baba to Saejima
"But once I get squared with my dream in a way I can live with...I'll come back to you again. And when I do, please let me vow the exchange of brotherhood with you."
In Abashiri prison, he wears a light blue jumpsuit. After being rescued by Saejima in the snowy mountains, he wears a dark brown jacket, with jeans and black boots. During his attempt at assassinating Daizo Kitakata, he wears a visor hat, and a bubble-jacket. He takes both of them off during his fight with Saejima, revealing a black turtleneck sweater. He wears a similar outift during his time in the Japan dome, with a visor cap. But instead of a bubble jacket, wears a dark military vest.
While his exact and whereabouts and details regarding his person prior to the events of Yakuza 5 are unknown, he claims to have belonged to the Kitakata Family active in Tsukimino, Hokkaido. In reality, he had been working with the Kuroha Family as an assassin, and was sent to Abashiri Prison 6 months prior to the game's events to monitor Saejima during his time in jail, making sure he gets out at the exact right time.
Baba is first seen as an inmate in Abashiri Prison, sharing a cell with Saejima. Supposedly he has been incarcerated for the murder of a member of the Kitakata Family for the last 10 years and has been moved to Hokkaido recently to finish his sentence, anticipating his parole, while he struggles with the prospect of being released. Saejima befriends him during their shared time in prison, as they are able to bond over their similar past as yakuza, while having been expelled from their families.
As Saejima refuses to bow to the harassment of Kugihara, another inmate, and his gang, they take to put pressure on Baba and eventually frame him for stabbing another inmate during a struggle. Baba's application for parole is compromised by this, though Saejima, and his other cellmates, take the investigation into their own hands and are able to clear Baba's name.
Shortly after, following the supposed death of Goro Majima, Baba is enlisted by Abashiri's deputy warden, Kosaka, to accompany Saejima in his prison break following the mysterious rejection of his parole. After fending off the horde of inmates, including Kugihara, they manage to escape. However, following the chase by a group aiming to prevent them in the forest outside the prison, Baba falls off the snowmobile he and Saejima fled on and is lost in the woods, in danger of freezing to death. He was eventually attacked by Yama-Oroshi, but was rescued by Saejima and Okudera. After Saejima helped the villagers vanquish the Yama-Oroshi threat, they went off to Tsukimino in order to find out the truth about Majima's persumed death. They planned to kidnap the patriarch of Kitakata Family, Daizo Kitakata, in order to gain information.
During the winter festival, they manage to convince Kitakata to tell everything about Majima. However, he was suddenly shot by Baba in order to keep his mouth shut. Saejima chases him and finds out the truth about Baba; he had been sent to Saejima's prison to make sure he got out at the right time, and was never a part of the Kitakata family to begin with. He also tells the revelation of how he hired Hiroshi Kugihara to give Saejima more time in prison. As Baba is about to shoot Saejima, he hesitates to do it due to Saejima showing undying loyalty and wisdom to Baba, even after he knows who he really is, not to mention saving him at the snow mountain. Baba then attempts to shoot himself but was stopped by Saejima and challenged by him. Baba fights off against Saejima, but is defeated. Baba then tells Saejima that one day he wishes he could officially be his sworn brother, and leaves in order to avoid Kurosawa and his men.
During final chapter, he tails and confronts Kazuma Kiryu at Kamurocho and spar with him for a while until he got beaten as well. Kiryu and Baba go to New Serena and talk for a while about the current situations. Kiryu also tells Baba to tell Haruka to never give up. In which he did when he goes to Haruka Sawamura and talks to her about Kiryu and trying to convince her to see him, but she didn't have the courage to do so.
During Haruka's concert at Tokyo Dome, it is revealed that he was sent by Kurosawa to assassinate Haruka with a sniper rifle. However, having a change of heart, Baba refuses to kill her and goes to leave until he was confronted by Shinada. They both fight for a while but eventually got defeated as well. Ashamed of himself, Baba attempts to commit suicide using his own sniper rifle and tells Shinada to tell his apologizes to Saejima. Thankfully, his other friends at prison, Himura, Oshima, and Kousaka, arrive to rescue Baba and comfort him. He was later watching the rest of the concert with his friends and Shinada before returning to Abashiri.
Baba is a proficient hand-to-hand combatant, due to his background as an assassin.
- The only fighting playable character he never fights in Yakuza 5 is Shun Akiyama.
- His fighting style would later be reused for Hiroshi Hayashi in both Yakuza Kiwami and Yakuza Kiwami 2.