Takeshi Yamada is the father in the Yamada family, working as an ordinary salaryman. He is portrayed as a diligent worker, contrasting with his wife and daughter in responsibility and work ethic. His car is a piece of junk. His hobbies include pachinko and golf. Takeshi is married to Matsuko Yamada, and they have two children: Nonoko, a third-grade elementary student, and Noboru, a junior high school student. Shige Yamano, Matsuko's mother, lives with them as the grandmother. The family also has a pet dog named Pochi.

Minor background elements shifted over time regarding Takeshi's extended family. His older brother Yoshio initially ran a farm in their hometown in earlier serializations. Following their mother's death, Yoshio moved in with the Yamada family and opened a bakery near their home, reflecting a narrative adjustment to the family's living situation and occupations.

Within the family dynamic, Takeshi often serves as the comically serious figure, reacting to everyday situations with exaggerated or mismatched seriousness. He faces routine family challenges like household chaos and interpersonal quirks but remains a grounding presence. His interactions highlight the family's humorous slice-of-life experiences.