[3] The ships of this class are currently the largest surface combatants of the JMSDF, taking over the mantle previously held by the Hyūga-class helicopter destroyers.

The modifications have been controversial as they seemingly violate Japan's post-World War II pacifist constitution, which restricts the country from possessing highly offensive weapons, such as aircraft carriers.

In September 2011, The Asahi Shimbun[14] reported that the Ministry of Defense was to proceed with a budget request calling for funds for the construction of the planned second unit in the class.

[5] The biggest warships in Japan's fleet since World War II, "raised eyebrows in China and elsewhere because it bears a strong resemblance to a conventional aircraft carrier"[5] and has been described by the Chinese as an "aircraft-carrier in disguise.

"[20] Though called a destroyer, provisions aboard the vessels indicated that the ships could be used in the future to launch fighter jets (F-35B) or other fixed wing aircraft.

[21][22][23][24] In December 2017, several sources including Reuters and Yomiuri Shimbun reported that the Japanese government was contemplating modifying the Izumo class to operate F-35B STOVL aircraft.

[26][27] The plan quickly raised criticism from China, where government officials reacted negatively and urged Japan to "act cautiously".

[28][29] Later, in February 2018, the Yomiuri Shimbun reported that Japan was planning to acquire 40 F-35Bs, the Short Take-off and Vertical Landing (STOVL) variant of the Lockheed Martin Lightning II Joint Strike Fighter (JSF), which could be operated from the Izumo class with some modifications to the ships.

[35][36] The modifications will reinforce the decks of the Izumo-class ships to support the additional weight of F-35B, as well as the heat and forces from the jets during vertical landing.

Initial modifications include strengthening the heat resistance of the deck and installing power supply equipment to enable the departure and arrival of the F-35B.

[45] [46] On 3 October 2021, two USMC F-35Bs performed the first vertical landings and horizontal take-offs from JS Izumo, marking the first time in more than 75 years that a fixed-wing aircraft operated from a Japanese carrier.

For the first time, the ship showed its 'carrier-ised' appearance, with the bow changed to a rectangular shape and a sign painted on the deck for landing and taking off aircraft.