"Wagnaria!!" is set in a family restaurant named Wagnaria, located in Hokkaido, Japan. The series revolves around the daily lives and interactions of its quirky staff members, blending slice-of-life comedy with lighthearted character-driven storytelling. The protagonist, Sōta Takanashi, is a high school student who begins working part-time at Wagnaria. Despite his youthful appearance, Sōta has a peculiar fascination with small, cute things, which often leads to humorous situations. His immediate supervisor, Popura Taneshima, is a petite and energetic girl who is often mistaken for a child due to her height, a source of constant frustration for her.

The restaurant’s manager, Kyōko Shirafuji, is a carefree and somewhat lazy individual who spends most of her time playing video games in the office, leaving the bulk of the work to her employees. Her laid-back attitude contrasts sharply with the diligent and serious head waitress, Yachiyo Todoroki, who wields a katana and is fiercely protective of her role. Yachiyo harbors unrequited feelings for Jun Satō, the chef, who is oblivious to her affections and often preoccupied with his own eccentricities, such as his obsession with collecting figurines.

Other notable staff members include Mahiru Inami, a waitress with severe androphobia, causing her to instinctively punch any man who comes too close. Despite this, she forms a tentative friendship with Sōta, who helps her gradually overcome her fear. Aoi Yamada, another part-time worker, is a clumsy and naive girl who often causes chaos in the restaurant but is endearing to her coworkers. The dynamics between these characters drive much of the humor and emotional moments in the series.

The narrative unfolds through episodic vignettes, focusing on the comedic and sometimes heartfelt interactions among the staff as they navigate their personal quirks and relationships. The restaurant serves as a central hub where their lives intersect, creating a sense of camaraderie and community. While the series primarily emphasizes humor, it also touches on themes of friendship, personal growth, and the challenges of balancing work and personal life. The characters’ distinct personalities and the absurd yet relatable situations they find themselves in make "Wagnaria!!" a charming and engaging exploration of everyday life in an unconventional workplace.