The B7A "Ryusei" (originally designated AM-23 by Aichi) was designed in response to a 1941 16-Shi requirement issued by the Imperial Japanese Navy Air Service for a carrier attack bomber that would replace both the Nakajima B6N "Tenzan" torpedo plane and the Yokosuka D4Y "Suisei" dive bomber in IJN service. It was intended for use aboard a new generation of "Taihō"-class carriers, the first of which was laid down in July 1941. Because the deck elevators on the "Taihō"s had a larger square area than those of older Japanese carriers, the longstanding maximum limit of on carrier aircraft length could now be lifted.