Tsukuba Naval Air Base / Tomobe Airfield

The primary closure was due to military conversion and disarmament. Following WWII, the Imperial Japanese military was dissolved, and its bases were either dismantled, repurposed, or handed over to Allied forces. The later closure of the small civilian airfield was due to a combination of economic non-viability and the land being redeveloped for other purposes, including an industrial park and a Japan Ground Self-Defense Force (JGSDF) camp.

The former airfield site is now used for multiple purposes. The original headquarters and command building has been preserved and now operates as the 'Tsukuba Naval Air Base Memorial Museum' (筑波海軍航空隊記念館), dedicated to the history of the base and its personnel. A significant portion of the site is occupied by the Japan Ground Self-Defense Force (JGSDF) as Camp Kasama. Other areas have been converted into the Kasama-Tomobe Industrial Park and agricultural land. While the airfield is closed, remnants of the original concrete runways and taxiways are still visible in aerial imagery, bisected by modern roads and developments.

Tsukuba Naval Air Base holds significant, albeit somber, historical importance. Established in 1938 by the Imperial Japanese Navy, it was a major training center for naval aviators, particularly for pilots of carrier-based attack aircraft and bombers. Its most notable role came in the final stages of World War II when it became a primary base for the formation and training of Kamikaze (Special Attack) units. The base was home to the 'Jinrai Butai' (Thunder Gods Corps), the unit that operated the Yokosuka MXY-7 'Ohka', a rocket-powered, human-guided anti-shipping suicide bomb. The base's original headquarters building and surrounding area were used as a major filming location for the 2013 Japanese war drama 'The Eternal Zero' (永遠の0, Eien no Zero), which greatly increased public awareness of the site's history.

Effectively zero. The site has been extensively redeveloped with a museum, an active military camp (JGSDF), and an industrial park. The original aviation infrastructure is fragmented and degraded. Furthermore, the region is served by the nearby Ibaraki Airport (IBR / RJAH), a joint civil-military airport, making any new airfield in Kasama redundant and economically infeasible. There are no known plans or prospects for reopening the site for any form of aviation.