Daitetsu Ōsawagi serves as patriarch of the Ōsawagi family in Urayasu, Chiba Prefecture. He shares his home with his wife Junko, their four children—Kotetsu, Haru, Sakura, and Yūta—and his father Kintetsu. As the central adult male figure, Daitetsu is integral to a family unit defined by extreme and preposterous behavior where mundane daily events rapidly escalate into chaotic, large-scale disturbances. Simple occurrences, like eating out or a child getting sick, routinely spiral into uncontrollable and exaggerated situations engulfing the entire household.

Available sources across the original manga, anime series (both 1998 and 2014), and the 2020 live-action series focus solely on Daitetsu's role within this collective family dynamic. His portrayal remains consistent as a participant in the family's shared antics; no detailed background story, personal history, individual character development, or narrative arc is documented.