"Nichijou - My Ordinary Life" is a slice-of-life comedy anime that revolves around the daily lives of a group of high school students and their interactions with the eccentric world around them. The series primarily focuses on three close friends: Mio Naganohara, Yuuko Aioi, and Mai Minakami. Mio is a diligent and artistic student with a strong sense of responsibility, though she often finds herself caught in absurd situations. Yuuko is energetic and impulsive, frequently struggling with schoolwork and prone to over-the-top reactions. Mai is quiet and deadpan, often engaging in bizarre and unpredictable behavior that contrasts sharply with her calm demeanor.

The narrative also intertwines with the lives of other characters, such as Hakase Shinonome, a child prodigy who lives with her robot caretaker, Nano. Nano, despite being a highly advanced robot, longs to live a normal life and attend school like her peers. Their household is further complicated by the presence of Sakamoto, a talking cat who serves as a reluctant guardian figure. The series also features the school’s principal, who has a peculiar habit of engaging in physical challenges with a deer, and various classmates and teachers who contribute to the chaotic yet endearing atmosphere.

The plot is episodic, with no overarching storyline, instead presenting a series of comedic vignettes that highlight the absurdity of everyday life. These vignettes range from mundane activities, such as studying for exams or preparing lunch, to surreal and exaggerated scenarios, like characters engaging in over-the-top battles or encountering fantastical elements. The humor often stems from the contrast between the characters' deadpan reactions and the ridiculousness of the situations they find themselves in.

Despite its comedic tone, the series occasionally touches on themes of friendship, self-discovery, and the pursuit of normalcy, particularly through Nano’s desire to fit in and Yuuko’s struggles with her identity. The interactions between the characters are central to the narrative, with their relationships providing both comedic and heartfelt moments. The series balances its absurd humor with a sense of warmth, creating a unique blend of comedy and slice-of-life storytelling.