is a Japanese manga series written and illustrated by Hiroto Ida. It was serialized online via Shinchosha's Kurage Bunch website form October 2013 to May 2019 and was collected into eleven volumes. A 4-episode live-action television series adaptation aired between March 6 and 27, 2017, and a live-action film adaptation was released in July 2017, both starring Shotaro Mamiya. An anime television series adaptation produced by Asahi Production aired from April to June 2018. A new "light anime" television series adaptation produced by Imagica Infos and Imageworks Studio, titled , aired from January to March 2026.
Nori Kamitsuki, a high school student who transfers from Chiba Prefecture to a school in Gunma Prefecture after his family relocates. Nori initially looks down on Gunma, viewing it as rural and unsophisticated. However, he is immediately confronted by the region's fiercely proud students, who treat Gunma not as a prefecture but as a sovereign and powerful territory with its own unspoken rules.
Nori becomes embroiled in escalating conflicts with classmates who embody Gunma's extreme local patriotism, including encounters that parody territorial warfare, secret police, and survival trials. As he struggles to adapt, Nori learns the customs, rivalries, and exaggerated dangers associated with life in Gunma, gradually shedding his prejudices.
An anime television series adaptation produced by Asahi Production aired from April 2, to June 18, 2018, on Gunma TV and Animax. The ending theme is "So Happy", performed by Aya Uchida. Crunchyroll streamed the series.
A new "light anime" television series adaptation was announced on October 28, 2025. Titled You Don't Know Gunma Yet: Reiwa Version, the series is produced by AnimationID and animated by Imagica Infos and Imageworks Studio and aired from January 10 to March 14, 2026, on SKY PerfecTV!'s . The theme song is "JÃ Âmo Karuta ~Reiwa-ban" (JÃ Âmo Karuta~Reiwa Version), performed by Masayuki Deguchi. Remow licensed the series for streaming on the "It's Anime" free ad-supported streaming television (FAST) channel on Samsung TV Plus.