This year's 41st issue of Weekly Young Magazine announced a television anime adaptation of Kengo Hanazawa's Under Ninja manga on Monday. The sixth volume also contained the announcement on its wraparound band the same day.

Synopsis
A high school loner is given the part-time job of a lifetime as a modern day ninja tasked to perform international assassinations.

After World War II, Allied Command in Japan developed a new agency to help manage terrorism and violence within the Pacific region. The agency was staffed with ninja and they were initially tasked to handle domestic affairs. Eventually that program grew to its current form, managing 20,000 ninja across a range of domestic and international affairs. One of those ninjas happens to be Kudo. The seventeen-year-old high school loser is now poised to be the next line of defense against a potential surge in foreign assassins invading Tokyo. (Source: Denpa, edited)

Hanazawa began drawing the action comedy manga in Weekly Young Magazine in July 2018, approximately 1.5 years after ending the serialization of I Am a Hero. Kodansha published the fifth volume on March 5. Hanazawa is simultaneously serializing Takaga Tasogare in Big Comic Superior.

Denpa, LLC. licensed the manga in English last July and plans to publish the first volume in January 2022.

Manga special page: https://magazine.yanmaga.jp/c/underninja/

Source: Weekly Young Magazine official Twitter

Under Ninja on MAL