"Ganbare!! Nattō-san" is a short-form anime series that centers around Nattō-san, a personified nattō bean, and her daily life in a small Japanese town. Nattō-san is a cheerful and energetic character who embodies the sticky, fermented soybean dish she represents. The series explores her interactions with other anthropomorphic food characters, such as Miso-shiro, a miso soup, and Natane, a rapeseed blossom. These characters coexist in a whimsical world where food items live and behave like humans, engaging in everyday activities and forming relationships.

The narrative is episodic, with each short episode focusing on lighthearted and comedic situations. Nattō-san often finds herself in humorous predicaments due to her sticky nature, which becomes a recurring theme throughout the series. Her optimism and determination to overcome challenges, despite her quirks, drive much of the humor and charm. The interactions between Nattō-san and the other food characters highlight their unique personalities and the dynamics of their friendships.

The setting is a quaint, rural town that mirrors traditional Japanese life, with a focus on food culture and seasonal changes. The series incorporates elements of Japanese cuisine and traditions, using the anthropomorphic food characters to playfully explore these themes. The tone remains light and comedic, with no overarching plot but rather a series of vignettes that showcase the characters' daily lives and their amusing adventures.

The main characters include Nattō-san, who is the central figure, Miso-shiro, who serves as a calm and supportive friend, and Natane, who is often portrayed as a rival or foil to Nattō-san. Other supporting characters, such as various vegetables and condiments, add to the ensemble cast, each contributing to the humor and charm of the series. The simplicity of the premise and the brevity of the episodes make the series accessible and entertaining, with a focus on humor and the endearing qualities of its characters.