"Ani Ni Tsukeru Kusuri wa Nai!" centers on the comedic and chaotic relationship between two siblings, Shi Miao and Shi Fen. Shi Miao, the older brother, is a college student with a calm and responsible demeanor, often acting as the voice of reason. In contrast, Shi Fen, his younger sister, is a high school student with a mischievous and overbearing personality, frequently causing trouble for her brother. Despite their contrasting personalities, the siblings share a close bond, though their interactions are often filled with exaggerated antics and over-the-top humor.

The series primarily explores their daily lives, focusing on the absurd and humorous situations that arise from Shi Fen’s relentless teasing and pranks aimed at her brother. Shi Fen’s antics range from playful manipulation to outright schemes, often leaving Shi Miao exasperated but ultimately unable to stay angry at her. The dynamic between the two is further complicated by their friends and acquaintances, who occasionally become unwitting participants in Shi Fen’s schemes or add to the chaos in their own ways.

Recurring themes include sibling rivalry, familial love, and the challenges of balancing responsibility with personal desires. The humor is often derived from the exaggerated reactions of the characters and the absurdity of the situations they find themselves in. While the series is primarily comedic, it occasionally touches on more heartfelt moments, highlighting the underlying affection between the siblings despite their constant bickering.

The narrative structure is episodic, with each episode presenting a self-contained story that contributes to the overall portrayal of the siblings’ relationship. The series avoids heavy plotlines, instead focusing on lighthearted and relatable scenarios that emphasize the comedic aspects of sibling dynamics. Through its humor and character interactions, "Ani Ni Tsukeru Kusuri wa Nai!" offers an entertaining and exaggerated take on the complexities of sibling relationships.