Lol there are a lot of lawyers on here. Fact is that the Japanese were, after Guadalcanal, placed on the *strategic* defensive. With regard to the air war in the Pacific theater, their premier asset, their elite carrier squadrons, were beaten and broken. Japanese pilot quality decreased as half-trained pilots were rushed into service, partially the result of the profligate waste of air assets over Guadalcanal, e.g., Val dive-bombers sent on one-way trips, launched even though they lacked the range to return.
The Japanese fought fiercely and desperately for the Solomons, taking huge risks without regard to loss. Although their naval forces could often make these risks pay off, the land forces performed miserably, launching attacks through difficult terrain based upon faulty intelligence as to USMC numbers and fighting quality, then starving and dying on long retreats because, in their hubris, they believed defeat to be impossible and supplied their troops with only enough rations to get to Henderson.
This win-or-die mentality did not serve the Japanese well when they still had parity of forces with the US. As their losses mounted and the strength of the American forces increased exponentially, the Japanese were doomed in the Pacific theater. Overwhelmingly powerful surface squadrons could still make contact with CVEs at Samar, but it didn't matter. Its counterpart force was destroyed in Surigao Strait, and the Japanese carrier offensive at Leyte Gulf was conducted by toothless carriers with empty hanger decks. The Japanese surface forces were counterattacks against very long odds, but the Leyte Gulf carriers were simply a diversion.
This does not consider the immense increase in size, strength, and combat efficiency of the American fleet since the commencement of hostilities; the Japanese inability to replace their naval losses; the wholesale destruction of the Japanese merchant fleet by US submarines and aircraft; the resulting fuel shortage that would have kept the Japanese from using their remaining warships or adequately training aviation pilots; US strategic bombing resources freed for use by the defeat of Nazi Germany, or the American development of the atomic bomb.
The Japanese had lost the war by the end of the Solomons campaign. They were subsequently still capable of limited tactical offensive/counteroffensive action to a decreasing extent - just as the Japanese surrender delegation could have engaged in a fistfight with MacArthur on the deck of the Missouri - but it simply did not matter because it could not have changed the result.
Late war Japan would still be fun if I could shoot at B-29s with this thing: