"After-School Hanako-kun" is a spin-off manga series set in the same universe as "Toilet-Bound Hanako-kun," created by AidaIro. The story takes place at Kamome Academy, a school known for its supernatural occurrences and urban legends. The narrative revolves around the daily lives of the school’s supernatural beings and their interactions with humans, offering a lighter, slice-of-life perspective compared to the main series.

The central focus is on Hanako-kun, the ghost of a boy who haunts the girls' bathroom and is known as the seventh school mystery. Unlike the main series, which delves into darker themes and mysteries, "After-School Hanako-kun" explores comedic and whimsical scenarios involving Hanako-kun and his companions. Nene Yashiro, a human student who becomes Hanako-kun’s assistant, plays a significant role, often finding herself entangled in the supernatural antics of the school’s mysteries. Kou Minamoto, a young exorcist and Nene’s classmate, also appears frequently, adding to the dynamic with his attempts to understand and sometimes challenge the supernatural entities.

The episodic structure of the series highlights various school mysteries, such as the Misaki Stairs, the Clock Keepers, and the 4 PM Bookstacks, each with their own quirks and personalities. These entities interact with Hanako-kun and the human characters in humorous and often heartwarming ways, providing insight into their lives and relationships. The tone is lighthearted, with a focus on comedy and character interactions, though occasional moments of emotional depth and backstory are woven into the narrative.

The artwork retains the distinctive style of the main series, with expressive characters and detailed backgrounds that enhance the whimsical atmosphere. The spin-off serves as a companion piece, offering fans a deeper look into the world of Kamome Academy and its inhabitants while maintaining a standalone appeal for those new to the franchise. The series balances humor, supernatural elements, and character-driven storytelling, making it an engaging addition to the "Toilet-Bound Hanako-kun" universe.