Yokosuka Naval Airfield was located on the Yokosuka Naval Base near Oppama, and was part of the defense of Tokyo during the waning days of the war. The base was one of the first occupied by the US following the end of WWII, and is still home to a major US presence in Japan, including support for Carrier Strike Group Five and the USS Ronald Reagan.
The Nakajima J1N1-S Gekko (“Moonlight”) [Low center and low left side, just in frame] was developed for recon and night fighting, and was later repurposed as a kamikaze aircraft (as were most Imperial Japanese) airplanes. As a night fighter, the type was equipped with 20mm cannon, either 4 firing in up and down pairs, or 2 or 3 all firing upwards. The aircraft would be fitted with 250 kg bombs for kamikaze missions. The night fighter missions were moderately successful, with close to three dozen B-29s being shot down by Gekkos. The J1N was sluggish and awkward however, and was far less capable as a Kamikaze. After the Japanese surrender, the US gathered 145 “interesting” aircraft and shipped them back to the States. After examining the aircraft’s engines and equipment three of the four Gekkos were scrapped, but one aircraft captured at Yokosuka was placed in storage, first by the USAAF, then by the Smithsonian. In 1979 the Gekko was selected for restoration, and by 1983 it was complete and placed on display, first at the Air and Space Museum in DC, then moved to the Udar-Hazy Center. One of the two J1N aircraft in this picture is likely that plane.
The bulk of the planes in this image are Mitsubishi G4M Isshikirikukō (Navy Type 1 attack bomber), known by crews as Hamaki (“Cigar”). The G4M was given the Allied reporting name “Betty” and was operated by the IJN from the beginning to the end of the war. Hamaki were used in the bombing of Clark Field in the Philippines the day after Pearl Harbor was attacked, and, along with G3M “Nell” bombers, sunk HMS Prince of Wales and HMS Repulse on December 10th 1941. As the war dragged on the type was upgraded several times, mainly adding armor to the fuel tanks and crew compartments as well as defensive guns. Mitsubishi also built 30 as G6M Navy Type 1 wingtip convoy fighters, armed with three 20mm cannon and one 7.7mm machine gun. The G6M were later modified into transports. The final use of the Betty was as a carrier plane for MXY-7 Ohka (“Cherry Blossom”) [Allied reporting name “Baka”, “Fool”] Kamikaze rocket planes. Of 2400 Hamaki built, none remain in complete condition, though several have been salvaged, and one plane, cut apart for reasons unknown, is retained by the Smithsonian. As with the J1N1, the plane was captured at Yokosuka after the war.
At lower right, the fin and rudder of a Yokosuka D4Y Suisei (“Comet”, Allied reporting name “Judy”) are visible. The type was developed as a carrier-based dive bomber, though it was also used as a recon plane and night fighter, and again as a Kamikaze later in the war. Of the 2000 produced, only two remain; one was restored and is on display at the Yūshūkan War Museum in Tokyo, and another was salvaged from Indonesia in 1991 and is on display at Planes of Fame in Chino, CA.