"ATASHIn'CHI" is a slice-of-life comedy anime that revolves around the daily lives of the Tachibana family, a quirky and endearing household navigating the ups and downs of ordinary life. The series is episodic, with each episode presenting self-contained stories that highlight the family's humorous and heartwarming interactions. The Tachibana family consists of four members: the father, a hardworking but often clueless salaryman; the mother, a cheerful and resourceful homemaker with a penchant for frugality; their teenage daughter, Mikan, who is energetic and occasionally mischievous; and their young son, Yuzuhiko, who is curious and often the voice of reason despite his age.

The narrative focuses on the family's everyday experiences, from mundane tasks like grocery shopping and school events to more unusual situations, such as dealing with eccentric neighbors or embarking on spontaneous family outings. The humor arises from the family's relatable dynamics, exaggerated reactions, and the occasional absurdity of their circumstances. The father's attempts to assert authority often backfire, while the mother's creative solutions to household challenges provide a steady source of comedy. Mikan's teenage antics and Yuzuhiko's innocent observations add layers of charm and wit to the series.

The anime does not follow a continuous plot but instead thrives on its episodic structure, allowing viewers to drop in and out of the Tachibana family's world without needing to follow a linear storyline. The characters' personalities and relationships remain consistent, providing a sense of continuity despite the lack of an overarching narrative. The series captures the essence of family life, emphasizing the humor and warmth found in everyday moments. Through its lighthearted tone and relatable scenarios, "ATASHIn'CHI" offers a nostalgic and entertaining portrayal of family dynamics.