Yamataian aircraft carrier Yumiori

During the 2010 Masukan War, Yumiori became the first aircraft carrier to be disabled in combat since the Second Escar-Varunan War.

Development and design
During the latter half of the 20th century, the Yamatai Imperial Navy drafted the Imperial Navy 21st Century Expansion Plan, which ambitiously planned for the construction of three supercarriers by 2010. However, following severe defence cutbacks in the aftermath of the 1997 Hasukuni earthquake, the supercarrier plan was abandoned in favour of building smaller V/STOL carriers to save costs on not only the development and construction of the supercarriers but also the development of new carrier-based fighters, as the Imperial Navy already had the V/STOL Ki-40 Tengu in service. This resulted in the design of the Sayashi-class aircraft carriers.

In addition to advanced command and control capabilities, the Yumiori also had powerful anti-submarine and anti-aircraft combat capabilities with a VLS missile system. Keeping with Imperial Navy doctrine, the Sayashi-class carriers and their air wings are intended to operate as escorts for the Imperial Navy's missile cruisers, with the ship capable of carrying out anti-submarine warfare and aerospace denial with its own equipment and air wing of ASW helicopters and V/STOL multirole fighters.

Construction and career
The vessel was laid down on 30 May 2002 and launched on 21 August 2003 by Fukuda Marine Engineering at Awara. Yumiori was commissioned into service on 16 March 2005, joining the 2nd Carrier Division with her home port at Awara.

Yumiori was involved in typhoon disaster relief efforts in Shojin as part of the Imperial Navy's participation in 2007. In 2009, Yumiori participated in the bi-annual Heian Cooperation Organisation marine exercises. She also carried out a goodwill visit to Amphia in late 2009.

2010 Masukan War
In 2010, Yumiori and the 2nd Carrier Division were dispatched to Masuka as part of the HECO coalition force. Her commander at the time was Captain Iwasaki Daisuke, while Rear-Admiral Kawashima Nori, commander of the 2nd Carrier Division, also used Yumiori as his flagship. The coalition fleet also included the Hotaru as well as the Chiseian fleet carriers Kamushain and Shakushain. The smaller Yamataian carrier wings were designated to provide air support missions for ground operations while the longer-ranged Chiseian fleet air forces carried out air superiority and missions.

On 12 April, the first day of the fighting, fighters from Yumiori supported the Yamatai Special Naval Landing Force as they made their landings. Yumiori and its air wing continued to provide air support for the next few days, also acting in a secondary role as a helicopter base for air-mobile coalition forces.

On 26 April, Yumiori suffered a systems failure that resulted in the ship's radar system going offline. At around 8 PM local time, Rear-Admiral Kawashima Nori decided to transfer his flag to the cruiser and departed Yumiori with his staff in a  helicopter. At the same time, a flight of Chiseian utility helicopters was also on approach to Yumiori for routine refuelling operations. Due to the malfunctioning radar system on Yumiori, the destroyer was to provide radar coverage while Yumiori repaired the fault. At some point during this window, three anti-ship missiles were suddenly fired from a Masukan vessel disguised as a civilian trawler. Two of the missiles were intercepted by Yumiori's CIWS systems, but the third managed to strike Yumiori amidships, causing damage to the superstructure, destroying two Ki-62 fighters, and starting an uncontrollable fire within the hangar deck. The trawler was immediately destroyed by an anti-ship missile from the destroyer Minazuki.

32 sailors were killed and 148 were wounded, with an additional 13 killed and 63 wounded in the hours after the attack by the fires. The hangar fire took over six hours to be brought under control, during which the bulk of Yumiori's crew was evacuated to the other nearby Imperial Navy ships. Yumiori was towed out of the combat zone by the destroyer. Civilian tugboats took over once the vessel was out of the combat zone, and Yumiori arrived at Shirada Shipyard on 30 April. Yumiori was the first aircraft carrier to be disabled in combat operations since the Second Escar-Varunan War, and the only coalition ship damaged by enemy fire during the 2010 Masukan War.

Investigation
After the conclusion of the war, an official inquiry was opened into the incident. The disabling of a modern aircraft carrier was a massive shock to the Imperial Navy and the wider global military community, especially more so due to the wide technological disparity between the HECO coalition forces and the Masukans in the war. The attack on Yumiori was widely studied by the Imperial Navy and allied foreign experts to examine the results of a conventional attacks on modern aircraft carriers.

A thorough investigation determined that a combination of factors resulted in the success of the attack, beginning with the faulty radar system that had not been designed to operate for prolonged periods in the tropics. The aged radar systems of the Minazuki were also found to have had trouble distinguishing the enemy missiles from the large amount of helicopter traffic in the airspace at the time, preventing a timely response with anti-aircraft missiles. There was also deemed to have been an intelligence failure as the disguised Masukan ship had previously been spotted in the combat area but had been dismissed as it was assumed to be a civilian vessel egressing from the area after perviously being ordered to by a Yeongseoni patrol aircraft. Finally, there was a general sense of complacency due to the perceived low military capabilities of the Masukan military.

Captain Iwasaki Daisuke subsequently resigned from the Imperial Navy along with several of his officers. Every crew member of the Yumiori, including the dead, were awarded the Medal of the Radiant Sun 2nd Class, and several crew members who endangered themselves attempting to rescue their fellow crew were also awarded accordingly.

After the investigation concluded, Yumiori was examined and the repair cost was found to exceed the Imperial Navy's previous estimates. The impending launch of the carrier Yakushi also brought into question the need for Yumiori. She was subsequently decommissioned 19 June 2012 and sold for scrap in 2015 in a controversial move.