第一航空戦隊
On his return to Japan, he was assigned to the First Carrier Division and met with Yamamoto in early February 1941, during which time Yamamoto presented some ideas for attacking the U.S. Pacific Fleet. Genda warmed to his ideas. Genda had previously considered an attack on Pearl Harbor in 1934 and had discussed the possibility then with Takijirō Onishi. Genda emphasized to Yamamoto that "secrecy is the keynote and surprise the all-important factor." Genda felt that the task was "difficult, but not impossible" and began working on the details of the plan. Genda favored a three wave attack using six aircraft carriers for a successful air strike. Genda was responsible for much of the training, especially in the new tactics of shallow-water torpedo use, effective use of level-bombing by tactical aircraft, and coordinating several aircraft carriers simultaneously. He played a key role in persuading IJN leaders to name Mitsuo Fuchida, his classmate at the Japanese Naval Academy, as the leader of the air attack.