"Ane Log" is a short-form anime series that revolves around the comedic and often exaggerated dynamics between three sisters and their interactions with their younger brother. The story primarily focuses on the eldest sister, Moyako, who harbors an intense and obsessive love for her brother, Kazushi. Moyako's over-the-top affection frequently manifests in absurd and humorous ways, often leading to chaotic and awkward situations. Her behavior is driven by a mix of genuine care and an exaggerated sense of possessiveness, creating a recurring source of comedy throughout the series.

The middle sister, Kojika, contrasts sharply with Moyako. Kojika is more reserved and level-headed, often serving as the voice of reason amidst the chaos. However, she is not immune to the family's eccentricities and occasionally finds herself drawn into the antics. The youngest sister, Kotoha, is cheerful and carefree, often acting as a mediator or providing comic relief with her innocent and sometimes naive perspective. Despite their differences, the sisters share a close bond, though their interactions with Kazushi often highlight their contrasting personalities.

Kazushi, the younger brother, is the central figure around whom much of the humor revolves. He is often the target of Moyako's overbearing affection and finds himself caught in the middle of his sisters' antics. While he cares for his sisters, he is frequently exasperated by their behavior, particularly Moyako's relentless advances. The series explores the comedic tension between Kazushi's desire for a normal life and his sisters' inability to provide it, resulting in a series of lighthearted and exaggerated scenarios.

The narrative structure of "Ane Log" is episodic, with each episode presenting a self-contained story that builds on the established dynamics of the characters. The humor is derived from the exaggerated personalities of the sisters and their interactions, often pushing the boundaries of absurdity while maintaining a light-hearted tone. The series does not delve deeply into dramatic or emotional arcs, instead focusing on delivering consistent comedic moments through its characters' quirks and relationships. Overall, "Ane Log" offers a straightforward and entertaining portrayal of sibling relationships, emphasizing humor and exaggerated character traits.