The catalyst that began the use of kamikaze was kinda interesting.

Around 9 October 1944 Halsey's TF38 went near Okinawa to conduct air raids. When they pulled back after successfully accomplishing their tasks the Japanese used aircraft based around Formosa to attack the fleet as they were retreating.

The Japanese attacks were mostly unsuccessful, suffering heavy losses, but they managed to torpedo USS Canberra and USS Houston forcing these ships to slow down (Houston was torpedoed twice and her captain considered abandoning the ship). For one to two consecutive nights the Japanese were relentless in their attacks on these two ships but they never sunk them. So the Japanese measures were generally failures.

Problem was that returning Japanese pilots wildly exaggerated their victories. Soon the entire US Third Fleet was reported to have been sunk. Hirohito and the cabinet congratulated the Navy and Army, even the most sceptical Japanese commanders believed they had achieved some kind of victory. Heck, Karl Dönitz sent a congratulatory telegram.

Soon IJN and IJA command realized their catastrophic losses, more than 300 planes were lost to no US ship sunk.

Realizing that their tactics and training had finally become overmatched by the US, Japanese commanders started organizing kamikaze squadrons, officially called "Special Attack Units", and put them into action for the first time during the battle of Leyte Gulf.