Shōshō Akatsuka, the younger brother of Daisaku "Taisho" Akatsuka, originated as a character specifically created for the first anime adaptation in 1969. He has consistently appeared in every subsequent adaptation, including the 1988 and 1998 anime remakes.

Physically depicted as a toddler or infant, Shōshō possesses the ability to speak fluently despite his young age but cannot yet walk independently. To move around, he frequently rides on the back of the family cat, Dora. His appearance is often noted as unusual or distinct for a baby.

Shōshō exhibits deep admiration and loyalty toward Taisho, demonstrating "Big Brother Worship." He regularly accompanies Taisho during schemes or adventures, acting as a sidekick when Taisho's other companions are unavailable. Despite his infant status, Shōshō displays cognitive abilities "Wise Beyond Their Years," understanding complex situations and conversations comparable to older children. He serves as a "Morality Pet" for Taisho, bringing out Taisho's protective and kinder qualities during their interactions.

His primary relationships focus on family and pets. His defining bond is with Taisho, characterized by Taisho's "Big Brother Instinct" and protectiveness. Shōshō's dependence on Dora for transportation establishes a functional relationship with the cat.

Across all media, Shōshō remains "Only Known by Their Nickname." While Taisho received the full name Daisaku Akatsuka in the 1988 adaptation, Shōshō's real name is never revealed. "Shōshō" (meaning "Major General") functions solely as a nickname, contrasting with Taisho's title of "The General."

The character maintains a consistent role and personality throughout all adaptations, with no significant evolution or backstory provided beyond his established dynamics.