The Taiho was to be built under the 4th Reinforcement Program of 1939. The basic design was based on the Shokaku class.
The Taiho was fitted with an armored flight deck, one of only two in the Japanese Navy, which caused it to be top heavy. As a result one deck was removed from the initial design.
The flight deck was designed to withstand an 1,000 lb bomb.
Two elevators were installed in the flight deck.
The bridge was designed to have the funnel go through it.
There were two hangars with the bottom one almost near the waterline. The hangars did not have armored sides. The height of the hangars was 16' 6".