Japanese bomber and attack plane losses were often pretty appalling even in the first year of the war, especially during attacks on warships.
The Japanese concluded they needed something like a 3:1 to 5:1 ratio of fighter cover to bombers in order to execute daylight strikes in contested airspace. Lots of Japanese strike packages over the Solomons and New Guinea in 1943 featured 10 or fewer bombers plus dozens of fighters split between close cover duty and enemy fighter-hunting. Even still the losses were sometimes unsustainably high.
I'd attribute a lot of the extremely high loss rate to allied anti-aircraft capabilities and not just air superiority. Attacking an American task force by the last year of the war meant flying into radar directed guns firing proximity fuze rounds and literally hundreds of 40mm Bofors and 20mm Oerlikon. It took a lot of training and skill to pull off accurate torpedo and dive bombing attacks even in more or less ideal conditions, let alone under that kind of fire. So not only did the losses become completely unsustainable, the results were fewer and fewer. By Formosa in October, 1944, you had some sizeable formations of Japanese attack planes and bombers achieving tactical surprise by approaching US carriers at low level below radar, and nevertheless incurring crippling and irreplaceable losses with only a handful of bomb and torpedo hits to show for it.
It figures kamikaze was an anti-ship tactic.
Not even the last year of the war :during the Santa Cruz Island battle (25–27 October 1942), even if tactically a japanese navy victory, they had to cope with an air defense they never saw before resulting with an appaling cost for the Kido Butai, in term of trained crewmen and pilots and above all of an invaluable veteran cadre loss (groups, squadrons and sections leaders).