Chikuwa is a Shiba Inu-type alien life form from the planet Geppler, sent to Earth as a spy with a mission to invade the planet. His primary strategy utilizes extreme cuteness to dominate and control the human population, making them emotionally dependent and subservient through overwhelming adorability.

He becomes integrated into the Inumiya household, living with the family members Madoka, Banjirō, and Nene Inumiya. His daily existence involves navigating the complexities of family life while pursuing his strategic objective, creating a dynamic where he must balance his alien mission with his adopted domestic role.

Interactions with other Geppler aliens occur, including encounters with a specific Geppler Alien operative, suggesting ongoing coordination of the invasion effort and the presence of a broader network of operatives working toward the same goal. These communications and their impact on the mission remain part of his activities.

His development is shown through the adoption of a pet-like identity and the forming of bonds with the human family. These bonds introduce complexity to the original mission parameters, creating internal conflict between the initial objective and the new emotional connections.