The downtown area.
'Furinkan' (風林館, Furinkan?) is a community in Nerima, Tokyo, Japan. The name means "wind forest hall" and it is the principal setting for the series. Although Furinkan is a fictional community, some scenes in the manga have been shown to have been modeled on actual places in Nerima's suburb of Shakujii-koen.
All of the main characters live in the suburban area of Furinkan, and most attend the eponymous local high school which is under the dark fist of Principal Kuno. The town has restaurants such as Ukyo Kuonji's okonomiyaki restaurant and Cologne's Cat Café. Many dojos are based in Furinkan, most notably the Tendo Dojo, home of the Tendo School of Anything Goes Martial Arts.
A common mistake, especially in fanfiction, is to refer to the area that the main characters live in as "Nerima". This is not entirely accurate, as Nerima is the greater region (or ward) in the Tokyo area in which Furinkan is found. The English Dub of OVA 10, Oh, Cursed Tunnel of Lost Love! Let My Love Be Forever, specifically refers to the location of the Cat Café and Okonomiyaki Ucchan's as "Furinkan neighborhood", though the word "Furinkan" does not appear in the original Japanese.