Although the B5N was substantially faster and more capable than its Allied counterparts, the American Douglas TBD Devastator monoplane (the U.S. Navy's first all-metal, carrier-borne monoplane of any type with retracting gear), and the British Fairey Swordfish and Fairey Albacore torpedo biplanes, it was nearing obsolescence by 1941.

[2][3] The B5N was designed by a team led by Katsuji Nakamura in response to a 1935 specification by the Navy for a torpedo bomber to replace the Yokosuka B4Y.

The first prototype flew in January 1937 and was ordered into production soon afterwards with the full designation Type 97 Carrier Attack Bomber[4] (九七式艦上攻撃機) (kyū-nana-shiki kanjō kōgeki-ki or kankō for short).

[5] Combat experience during the Second Sino-Japanese War revealed several weaknesses in the original B5N1 production model.

Keen to maintain the high performance of the type, the Navy was reluctant to add weight in the form of armor, and instead looked to obtaining a faster version of the aircraft in the hopes of outrunning enemy fighters.

The navigator/bombardier/observer position was equipped with a Type 90 bombsight, which was a long vertical tube located in the front-left of the seat.

[10] As with other IJN multi-seat aircraft, an individual bomber was commanded by the senior ranking crew member aboard, which could be the observer rather than the pilot.

One of the B5N2s carried Mitsuo Fuchida, the commander of the attack, with one high-level bomber from the carrier Hiryū credited with sinking the American battleship Arizona.

The B5N2 torpedo bombers also sank the battleships West Virginia, California, Oklahoma and Utah.

Replicas of the B5N2s were made using stretched fuselages from U.S. Canadian Car and Foundry "Harvard" - a variant of the North American T-6 Texan trainers, which were modified to represent Japanese aircraft for the movie Tora!