The 381 Kokutai was organized on October 1, 1943, as a fighter-bomber unit. On April 1, 1944, carrier aircraft types and night fighters were added and organized three hikotai, 602 Hikotai with 48 fighter-bombers, c/o Lt Kurosawa Takeo; 902 Hikotai with 24 night fighters, c/o Lt Matsumura Hideo; 311 Hikotai with 48 Zero Model 52 fighters, c/o Lt Kanzaki Kunio.
The details below are from photos featured in various Japanese publications taken in March 1944, in Toyohashi base, Aichi Prefecture, before the unit was dispatched to Borneo.
And another photo from here.
All the Zeros are Model 52s fresh out of the Mitsubishi factories except for the Zero in the photo above "81-113" which was Nakajima built.
Let's see a few interesting details.
All the aircraft have NMF propellers and spinners and have the last two digits of the tail marking repeated on the lower cowling lip.
No numbers are repeated on the wheel covers and the interior of the landing gear and wheel wells are in hairyokushoku; same color as the undersides of the aircraft.
Note the bomb rack under each wing.
Here's an illustration of the bomb from here, with more details.
Note the width of the IFF stripe and the cloth wrapped around the barrel of the 20mm wing cannon.
From the close-up below we can confirm that the wing top hinomaru are with a white surround. As are the fuselage hinomaru.
AFAIK, noone has released any kit or decals of these aircraft. Leave a comment if you know something.
BTW, the Zero Model 52 displayed in Yushukan, has 381Ku markings. Photo: Arawasi
From Toyohashi to Borneo is more than 400km, a rather long distance for a single engine aircraft and the Zeros of the 381Ku had to make stops at Kyushu, Okinawa, Taiwan and the Philippines. Once in Borneo they spent their time training and patroling until about August 1944.
On September 1, 1944, the unit had 40 602 Hikotai Zeros in Balikpapan together with eight 902 Hikotai "Gekko" night fighters. 32 Zeros, nine "Raiden" and two 602 Hikotai "Gekko" were based in Kendari and two 902 Hikotai "Gekko" were in Surabaya.
The publication "Nankai No Umiwashi-tachi" (The Imperial Japanese Navy Air Groups in the Southwest Pacific Theater) by DaiNipponKaiga, features 381Ku photos taken by photographer Abe Tetsuo when he visited Sorong base, West Papua in May 1944. Three Zeros stand out, let's see the details.
The "81-1183" was a Nakajima built A6M2 with cluster bombs under its wings. The hokoku inscription on the fuselage reads "Seram 1". It's highly unlikely the locals actually donated this a/c so the purpose of the ijnscription is unclear. Very unusually, the tail and about half the wing area had been painted in a lighter color and it looks exactly the same with the hairyokushoku of the lower surfaces.
The other photo close-up shows two more A6M2s also with lighter tails and wings.
Hasegawa has released kit no. 07411 in 1/48 with decal options for "81-1183" and "81-1146".
Rising Decals has released an extra in 1/72 with decals for all three aircraft and resin wing bombs.
The book "Tatakau Zero-sen" by Watanabe Yoji, published by Bungeishunju features a number of 381Ku photos taken at Degos airfield, Mindanao, in the Philippines in April 1944. Among them there is one of particular interest, here's a close-up.
As we saw before, the tail should be hairyokushoku and the cowling edge either white or hairyokushoku. I think the tail marking is a guess by the artist.
Behind the Kanzaki Zero is another the tail marking of which is partially visible. Again there is an illustration with some innacuracies.
I would also suggest that both aircraft had about half of the wing areas in hairyokushoku. The radio antenna should be shorter too.
In August 1944, the 381Ku was based on Ambon Island.
The Combat Report of the unit for an action on August 4, 1944, mentions:
07:05 - five Zeros took off (pilots: Tsuchida Katsuya, Oyama Kunio, Yoshimura Kazuo, Kimura Yutaka, Ohigashi (?) Yoshimi)
07:23 - a B-25 was spotted and was attacked. It emmited white smoke but managed to escape in the clouds
07:50 - returned to base
10:30 - received a report that enemy is apporaching the area and five Zeros took off again (pilots: Tsuchida Katsuya, Oyama Kunio, Yoshimura Kazuo, Kimura Yutaka, Kinoshita ?)
10:43 - attacked an enemy force of 28 P-38s and B-24s
Tsuchida Katsuya made a suicide attack crashed on an enemy aircraft and perished
Kimura Yutaka shot down one P-38
Yoshimura Kazuo was last seen evolved in air battle but failed to return
11:05 - three aircraft returned to base
The unit claimed two P-38s shot down on that day.
The only reference to that raid I was able to spot was from the site of the USAAF 9th Fighter Squadron "The Flying Knights", here.
On August 4th our planes again engaged in aerial combat. The 9th escorted B-24's to Liang on Ambon Island and encountered about six Zekes - the Jap (sic) navy's mainstay zero fighter. The enemy planes were flying above our bombers dropping phosphorus bombs on the formation but making no passes at our planes. The primary purpose of our planes being to protect the bombers, our pilots restrained their natural impulse and remained with the bombers rather than be lured away and leave our bombers open to attack by other Jap planes in the area. A P-38 from another squadron was seen at the mercy of a Zeke which was on its tail, so 2 of our pilots, Lts. McElroy and Hufford finally caught it in a steep chandelle, whereupon the Zeke exploded in mid-air. This is the 2nd plane shot down by McElroy; his first being a victory over Babo on 3 June.
This could be either the aircraft of Yoshimura or Tsuchida.
In September the unit had relocated to Menado and the Combat Report of September 2, 1944, mentions:
10:00 - a report arrived that an enemy force of seven B-24s, two B-25s and two P-38 is approaching, and two Zeros took off (pilots: Kamidaira Teshu, Murabayashi Sadao)
10:25 - Spotted one B-24, the two Zeros launched a combined attack of bombs and machine gun fire. The enemy aircraft was shot down.
11:20 - two Zeros returned to base
13:00 - four Zeros took off (pilots: Kutami Masayuki, Taura ?, Fukuyama Nobuyoshi, Sakaguchi Masahiro)
13:20 - started patrol
14:45 - returned to base. No enemy was encountered.
This source mentions:
Having completed the missions against Mindanao, the Fifth Air Force turned its medium and heavy bombers to the Celebes. This strangely formed island, roughly the shape of a "K' with the vertical stroke looped over the whole letter, lies between the Moluccas and Borneo. Although a single island it had been given a plural designation by early explorers who were puzzled by its peculiar conformation. To reach its western extremities would tax the range of B-24's from either Biak or Darwin, but its most important installations were located in the northeastern and southeastern peninsulas where even B-25's, staged at Noemfoor, could attack them. On the long northeastern peninsula which curls over the whole island, centering around Menado, the Japanese had built Langoan, Mapanget, and Sidate airfields. Japanese garrisons and some industrial activity had been noted in the towns of Menado (also headquarters of the Second Area Army), Gorontalo, and Tomohon. At the extremity of the northeastern peninsula, Lembeh and Bangka straits provided shelter for shipping, and Amoerang Bay, on the north coast of the northeast peninsula, was a shipping center. Less was known about the southeastern peninsula, but in addition to the old airfields at Kendari and Pomelaa the Japanese had developed five new airfields in the area-Baroe, Boroboro, Tiworo, Ambesia, and Witicola. As of 1 September the Japanese were believed to have 177 planes in the Celebes.80
A few B-24's and PB4Y's had bombed the Celebes earlier in August, but the first large-scale effort against the area was flown on 24 August by thirty-six B-25's of the 345th Bombardment Group, staging through Noemfoor. This mission successfully attacked merchant shipping in the Bangka and Lembeh straits, damaged the mine-layer Itsukushirna with near misses, and strafed and bombed storage areas at Lembeh.81 Except for reconnaissance planes and night-flying B-q's, the Celebes went free until 2 September chiefly because weather held off scheduled 345th Group strikes. On that date thirteen B-25's from the group tried to attack Langoan airfield, but when their fighter cover did not appear on schedule, the B-25's once again attacked shipping in the Lembeh Strait. On this mission the AA positions along the straits, aided by gunners on the damaged mine-layer, put up a curtain of flak which veteran pilots said was the most intense seen since Rabaul; two B-25's were shot down and two others so badly damaged that they were forced to land at Middelburg. This mission showed that the Celebes were too well defended for medium bombers.
This source mentions:
2 September 1944:
Lahbeh Strait, Celebes. Thirteen B-25s of the 345th BG attack Japanese installations along the strait. Six of the B-25s attack Lambeh Town and ITSUKUSHIMA. The minelayer throws up an intense barrage of AA fire that shoots down 2nd Lt Lloyd B. Bardwell's B-25D nicknamed the "Mexican Spitfire." ITSUKUSHIMA's AA fire also damages two other B-25's that later crash-land at Middleburg Island, NEI.
Bardwell ditches in the water about 7 miles from Lahbeh Island. Several survivors are seen. 2nd Lt Allan W. Lay flies top cover in B-25D "Hell's Fire". Soon, three Mitsubishi A6M "Zeke" fighters arrive. Two attack Lay's B-25 and the third strafes Bardwell's crew in the water. The Zekes shoot down Hell's Fire. The "Mexican Spitfire's" crew is never seen again.
According to other on-line sources, "Hell's Fire"crashed into the base of Mt. Tongkoko.
"Hell's Fire, #41-30278, 500th Bomber Squadron, 345th Bomber Group, Medium, U.S. Army Air Force.
Crew on that day was:
Burgess, James O ~ 2nd Lt, Co-Pilot, TN
Greger, Arthur L ~ 2nd Lt, Nav/Bmb, TX
LaBoy, Raymond A ~ S/Sgt, Radio Operator, NY
Lay, Allan W ~ 2nd Lt, Pilot, MO
Turner, John ~ S/Sgt, VA
Walker, Ray S ~ S/Sgt, AR