Imperial Japanese Air Force defending the Kuriles:

There is little or no accurate information about the Japanese air force in the Kuriles in 1945. The Russians recovered at least six unidentified but presumably A6M5 Zeke fighters, two unidentified single-engine bombers and a half dozen of older torpedo bomber, the B5N2 Kate, at the airfields on Shimushu (the most northward island of the Kuriles chain). Further up to 7 or 8 were claimed by the Soviet vessels, and some reports a Soviet vessel was crashed by an aircraft acting as a Kamikaze. It is known that in 1944 a force of 19 Zeros has been left as the Shimushu Detachment by Naval Air Group 203, when that group departed back to the Home Islands and thence to the Philippines (where it was destroyed). It is possible that a few Nakajima J1N1-S Irving night fighters were also left.

During 1943 and 1944, Japanese Army fighters on Paramushiro (the largest island at the northern end of Kuriles chain and southward of Shimushu) had included Ki.43 Oscar and Ki.44 Tojo interceptors, but the author of this article lacked IJAAF order of battle data to know what was still there in 1945, although several Oscars were seen as late as June.

The Soviet air cover and support for the Shimushu landings were provided by the 128 SAD, their 888 IAP had the P-63 Kingcobra, which they had received only in August 1945, before that they remained the last active Soviet fighter regiment with the I-16. The 410 ShAP, also of the same division also had converted to the P-63, in their case from the Il-2 (It is uncertain but possible that they may have been redesignated as 410 IAP.). The third regiment in the division flew a mixture of A-20 and SB bombers, and a few PV-1s which had been interned prior to August 1945. The naval torpedo bomber unit was the 2 MTAD (division), consisting of the 4 MTAP (Il-4 & DB-3), 49 MTAP (Il-4, A-20G, & A-20H), & 52 MTAP (DB-3).

?The commencement of the invasion fell between the atomic bombings of Hiroshima, on August 6, and Nagasaki, on August 9. Although Soviet leader Joseph Stalin had not been told much detail of the Western Allies' atomic bomb program by Allied governments, he was nonetheless well aware of its existence and purpose by means of Soviet intelligence sources. However, by virtue of the timing of the agreements at Tehran and Yalta, and the long term buildup of Soviet forces in the Far East since Tehran, it is clear that news of the attacks on the two cities played no major role in the timing of the Soviet invasion; the date of the invasion was foreshadowed by the Yalta agreement, the date of the German surrender, and the fact that on August 3, Marshal Vasilevsky reported to Stalin that, if necessary, he could attack on the morning of August 5.

At 11pm Trans-Baikal time on 8 August 1945, Soviet foreign minister Molotov informed Japanese ambassador Sato that the Soviet Union had declared war on the Empire of Japan, and that from August 9 the Soviet Government would consider itself to be at war with Japan. At one minute past midnight Trans-Baikal time on 9 August 1945, the Soviets commenced their invasion simultaneously on three fronts to the east, west and north of Manchuria. Though the battle extended beyond the borders traditionally known as Manchuria - that is, the traditional lands of the Manchus - the co-ordinated and integrated invasions of Japan's northern territories has also been called the Battle of Manchuria. Since 1983, the operation has sometimes been called “Operation August Storm”, after American Army historian LTC David Glantz used this title for a paper on the subject. It is also known by its Soviet name, the Manchurian Strategic Offensive Operation, the battle of Manchukuo and the Soviet invasion of Manchuria.

The Invasion of the Kuril Islands, also called Kuril Islands Landing Operation was the Soviet military operation aimed at capturing the Kuril Islands from the Japanese in 1945 as part of the Manchurian Strategic Offensive Operation when the plans to land on Hokkaido were abandoned. The operation took place between August 18 and September 1, by the 87th Rifle Corps (Guards General Lieutenant A.S. Ksenofontov) of the 16th Army (General Lieutenant L.G.Cheremisov) from the 2nd Far Eastern Front, including the elements of Kamchatka defense area (Major General A.R.Gnechko commanding), ships and transportation from the Petropavlovsk military base (Captain D.G.Ponomarev) and with the support from the 128th Airborne Division.

Successful military operations of the Soviet Army in Manchuria and South Sakhalin created the necessary prerequisites for invasion of the Kuril Islands, which had been occupied by the Japanese 91st Infantry Division (islands of Shiashkotan, Paramushir, Shumshu, and Onekotan), 42nd Division (Shimushiro), 41st detached regiment (Matua Island), 129th detached brigade (Urup Island) and 89th Infantry Division (islands of Iturup and Kunashiri). The Japanese commander was Lieutenant General Tsutsumi Fusaki.

Initial reconnaissance was undertaken by two mine trawlers TW-589 and TW-590 carrying a detachment of troops from the 113th separate rifle brigade (Captain-Lieutenant G.I. Brunshtein) on the 28 August, the landing taking place in the Rubetzu bay on the Iturup island. On the same day elements of the 87th Rifle Corps were landed by torpedo boats, mine trawlers and transports (departing from Otomari port) on the Kunashir, Shikotan and five smaller islands Sibotzu, Taraku-Shima, Uri-Shima, Akiuri, and Suiseto. The landings on Iturup were continued by the 355th Rifle Division which also landed on the smaller Urup island.