Atsuya Baba serves as the straight man (tsukkomi) in the comedy duo Homosapiens alongside Kensuke Shibagaki's funny man (boke). His optimistic, mild-mannered, and kind personality enhances his public appeal. Both attended the same high school before forming their partnership. Baba openly admires Shibagaki's comedic talent, crediting him as the duo’s genuinely funny member, and vows to quit comedy if he ever obstructs Shibagaki’s career.

Homosapiens segments air on "Japan Broadcasting," featuring Baba’s own segment "What Do I Eat for Lunch?" where he dines randomly with city residents. Privately, Baba plays the mobile game "Zooden" under the username "Homosapi Baba," hiding this hobby from Shibagaki, who criticizes it as a distraction from joke-writing. He uses his real surname in-game to engage with fans.

Baba’s interactions include Rui Nikaido of Mystery Kiss. After she disliked their jokes on their show, a chance train encounter led Nikaido to question if Baba resented younger comedians surpassing them. He admitted past frustration but revealed a shifted perspective: prioritizing happiness for peers’ successes over personal ambition. This outlook resonated with Nikaido, prompting them to exchange contacts and forge a friendship. Baba later provided Nikaido emotional support after she discovered Yuki Mitsuya’s corpse, though she withheld the full circumstances.

Baba’s animal appearance originates from protagonist Hiroshi Odokawa’s visual agnosia, which causes humans to appear as anthropomorphic animals; Baba is human in reality. The film *Odd Taxi: In the Woods* reconstructs series events and depicts post-series developments, including Baba’s appearance without introducing new character background or development beyond the established narrative.