It was a two-seat, single-engine, equal-span biplane seaplane used primarily by the Imperial Japanese Navy.
The first prototype of the Type 90-2 Reconnaissance Seaplane, or E4N1, inspired by the Vought O2U Corsair, flew in 1930.
The plane was redesigned as the Type 90-2-2 or E4N2, with a single main-float and twin, wing-mounted outriggers, powered by a cowled Nakajima Kotobuki 2-kai-I nine-cylinder air-cooled radial engine.
A carrier version with wheels and arrestor gear, the E4N2-C, was trialed by 5 aircraft but ultimately not accepted for use.
[2] Data from Japanese Aircraft 1910-1941 [2]General characteristics Performance Armament