Question: When was the ace of the Imperial Japanese Navy Air died who served during World War II and who was squadron mate of Toshio Ōta?

Context paragraphs:
Kawanishi H8K: The Kawanishi H8K (二式飛行艇, "Nishiki Hikōtei", Type 2 Flying Boat.  Commonly called as 二式大型飛行艇 "Nishiki Ōgata Hikōtei", 二式大艇 "Nishiki Daitei" or "Nishiki Taitei", Type 2 Large-sized Flying Boat) was an Imperial Japanese Navy flying boat used by the Imperial Japanese Navy Air Service during World War II for maritime patrol duties.  The Allied reporting name for the type was "Emily".

Imperial Japanese Navy Air Service: The Imperial Japanese Navy Air Service (大日本帝國海軍航空隊 , Dai-Nippon Teikoku Kaigun Kōkū-tai ) was the air arm of the Imperial Japanese Navy during World War II.  The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.

Hiroyoshi Nishizawa: Lieutenant Junior Grade Hiroyoshi Nishizawa (西澤 広義 , Nishizawa Hiroyoshi , January 27, 1920 – October 26, 1944) was an ace of the Imperial Japanese Navy Air Service during World War II.

Tainan Air Group: The Tainan Air Group (台南海軍航空隊 , Tainan Kaigun Kōkūtai ) was a fighter aircraft and airbase garrison unit of the Imperial Japanese Navy (IJN) during the Pacific campaign of World War II.  The flying portion of the unit was heavily involved in many of the major campaigns and battles of the first year of the war.  The exploits of the unit were widely publicized in the Japanese media at the time, at least in part because the unit spawned more aces than any other fighter unit in the IJN.  Several of the unit's aces were among the IJN's top scorers, and included Hiroyoshi Nishizawa, Saburō Sakai, Junichi Sasai, Watari Handa, Masaaki Shimakawa, and Toshio Ōta.

Kawanishi N1K: The Kawanishi N1K "Kyōfū (強風 "strong wind", Allied reporting name "Rex") was an Imperial Japanese Navy floatplane fighter.  The Kawanishi N1K-J "Shiden (紫電 "Violet Lightning") was an Imperial Japanese Navy Air Service land-based version of the N1K.  Assigned the Allied codename "George", the N1K-J was considered by both its pilots and opponents to be one of the finest land-based fighters flown by the Japanese during World War II.

Kōkūtai: A Kōkūtai (航空隊 ) was, during World War II and in the Imperial Japanese Navy, a type of aerial combat unit, similar to the Air Groups in service in the other armies and navies of the time (called "Group" in the British Royal Air Force, "Gruppe" in the German Luftwaffe, "Groupe" in the French Armée de l'Air etc.).  Although belonging to the Imperial Navy the Japanese Kōkūtai could be based at land or on board naval aircraft carriers and were constituted by hundreds of men and aircraft (that latters were distributed in smaller units called Hikōtai, the equivalent of squadrons).  For example, the famous 343 Kōkūtai (a fighter group, divided in three Hikōtai) was based at land while the 652nd Kōkūtai (a bomber group) was carrier-based.  As in general in the Imperial Japanese Navy Air Service, most pilots and aircrew members of a Kōkūtai were non-commissioned officers.

Japanese marine paratroopers of World War II: The Imperial Japanese Navy fielded naval paratroopers during World War II.  The troops were officially part of the Special Naval Landing Forces (SNLF or "Rikusentai").  They came from the 1st, 2nd and 3rd Yokosuka SNLFs.  The 2nd Yokosuka took no part in any airborne operations and became an island defensive base unit.  They were under the operational control of the Imperial Japanese Navy Air Service (IJNAS or "Dai-Nippon Teikoku Kaigun Koku Hombu").  "Rikusentai" paratroopers should not be confused with the Imperial Japanese Army paratroopers, known as "Teishin".

Imperial Japanese Navy in World War II: The Imperial Japanese Navy in World War II, at the beginning of the Pacific War in December 1941, was the third most powerful navy in the world.  During the first years of the war the Imperial Japanese Navy dominated the Western Pacific.  However, after a series of defeats it lost control of the Western Pacific and collapsed by the end of the war.  The naval air service was one of the most potent air forces in the world before its destruction in World War II.

Toshio Ōta: Toshio Ōta (太田 敏夫 , Ōta Toshio , 20 March 1919 – 21 October 1942) was a World War II Japanese fighter ace.  In early 1942, at the age of 22, he flew a Mitsubishi A6M Zero with the Lae based Tainan Air Group.  There the young petty officer, 1st class became one of the so-called "Clean-up Trio" of Japanese aces, along with his squadron mates Saburo Sakai and Hiroyoshi Nishizawa.

William Forbes-Sempill, 19th Lord Sempill: William Francis Forbes-Sempill, 19th Lord Sempill AFC, AFRAeS, (24 September 1893 – 30 December 1965) was a Scottish peer and record-breaking air pioneer who was later shown to have passed secret information to the Imperial Japanese military before the Second World War.  Educated at Eton, he began his career as a pilot in the Royal Flying Corps and then served in the Royal Naval Air Service and Royal Air Force during the First World War.  In 1921, Sempill led an official military mission to Japan that showcased the latest British aircraft.  In subsequent years he continued to aid the Imperial Japanese Navy in developing its Navy Air Service.

Supporting paragraphs: Toshio Ōta Hiroyoshi Nishizawa
Answer: October 26, 1944