Read Manga Under Ninja online in English. Also known as アンダーニンジャ and Andā Ninja.

Ninjas never truly disappeared from Japan. They slipped into offices, schools, agencies, and quiet apartment blocks, waiting for orders no ordinary citizen would ever notice. Kuro Kumogakure is one of the unlucky ones: a low-ranking, jobless ninja living like a shut-in until a long-delayed assignment pulls him back into service. His mission sounds almost ridiculous at first: infiltrate a high school using modern ninja equipment.

What begins with deadpan comedy and everyday boredom gradually opens into a strange hidden war, where rival ninja groups, advanced tools, and disposable soldiers move beneath the surface of normal society. Kuro may look lazy and detached, but his new role places him near conflicts far bigger than one undercover student mission, blending awkward slice-of-life moments with sharp, unpredictable action.

This series may appeal to readers who enjoy modern ninja fiction, dark comedy, and offbeat seinen action stories.