"Ninin Ga Shinobuden" is a comedic manga series that blends absurd humor, parody, and ninja tropes into a chaotic and entertaining narrative. The story centers on Shinobu, a young ninja-in-training, and her unconventional mentor, Onsokumaru, a self-proclaimed "ninja master" who resembles a small, floating, yellow, spherical creature with a penchant for mischief. Despite his bizarre appearance and questionable methods, Onsokumaru claims to possess unparalleled ninja skills, though his antics often undermine his credibility.

Shinobu, earnest and determined, strives to become a skilled ninja but frequently finds herself entangled in Onsokumaru's outlandish schemes. Their dynamic is a mix of mentor-student relationship and comedic rivalry, with Onsokumaru often derailing Shinobu's training with his absurd behavior. The series also features Kaede, Shinobu's childhood friend and a more traditional ninja, who serves as a foil to Onsokumaru's eccentricity. Kaede is level-headed and skilled, often providing a grounded contrast to the chaos surrounding Shinobu and Onsokumaru.

The plot unfolds in a series of episodic adventures, with the trio encountering various characters and situations that parody ninja lore and pop culture. These include rival ninja clans, bizarre enemies, and surreal scenarios that defy logic. The humor is often slapstick and over-the-top, with Onsokumaru's antics driving much of the comedic momentum. Despite the lack of a continuous overarching plot, the series maintains a consistent tone of irreverence and absurdity, with each chapter delivering self-contained comedic set pieces.

Themes of perseverance, friendship, and the absurdity of traditional tropes are woven throughout the narrative, though they are often overshadowed by the series' focus on humor and parody. The characters' interactions and the unpredictable nature of the story create a lively and engaging experience, appealing to fans of offbeat comedy and ninja-themed stories. "Ninin Ga Shinobuden" stands out for its unique blend of humor, unconventional characters, and playful subversion of genre expectations.