The Maritime Self-Defense Force is upgrading its Izumo and Kaga destroyers into de facto aircraft carriers, equipping them to operate the F-35B stealth fighter, which features short takeoff and vertical landing capabilities.
Performance tests conducted in October and November last year, with cooperation from the U.S. Navy and Marine Corps, confirmed that the upgraded Kaga can accommodate the F-35B without issue.
It’s being retrofitted to allow for STOVL aircraft, not “all type of aircraft”. They are not installing catapults, arresting gear, or the angled deck needed for CATOBAR operations. They won’t be launching Super Hornets, Growlers, F-35C’s (which are much more capable than the B models). They certainly won’t be operating E-2 Hawkeyes, “buddy tankers”, or electronic warfare aircraft. They will be reliant on long-range, land-based support aircraft for tankers, airborne early warning, electronic warfare, reconnaissance, etc.
True. It will definitely be a true carrier in the military sense. The F-35B is a very capable aircraft, and they will be able to operate a wide variety of helicopters and the Osprey.
Just to put it in perspective: It will be comparable to what the US navy calls an “Amphibious Assault Ship” (Wasp and America classes, carrying ~20 aircraft each) than its current “Carriers” (Nimitz and Ford classes, with ~90 aircraft each).