No it wasn’t, it was dreamy war-plan that was never to come to fruition:
Did you selectively ignore this? Yes Japanese troops were deployed along the border, but it was contingency planning, not a serious strategic plan simply because the Japanese knew their limitations:
In devising operational plans against the USSR, the hypothetical movements of the Soviet Far Eastern Army were a major consideration. The Japanese Army General Staff made the following estimate of the situation: the Soviets could be expect to commit 55-60 divisions to the Far Eastern Operations. They would launch simultaneous, converging offensives from the east, north and west of Manchuria. The enemy would strive to cut off communications between the Japanese homeland and the Asiatic continent. If war broke out with the Soviet Union, the most important problem would arise: how to terminate the hostilities? The Army General Staff feared that the Russian territory was so boundless that Japan would be unable to deal a finishing blow to the enemy…
After this secret conference, Imperial Headquarters ordered the implementation of the revised policy toward the Soviet Union by commencing large scale reinforcements of the Kantogun. To keep the true reasons secret, the build-up was called the “Special Manoeuvers of Kantogun” or KANTOKUEN for short. The 400,600 troops of the Kantogun suddenly rose to over 700,000 and some billion Yen in military funds were allocated. [b]These manoeuvres prepared the use of force against Soviet Union, based upon the prospect that the Russo-German war might rapidly take a favorable turn for Germany. In the event that force was used against the USSR, the new operational plan of 1939 was scheduled to go into effect, whereby simultaneous offensives were to be mounted north and east from Manchuria. Additionally the new plan included landings in Soviet Far East islands and coastal areas, and land operations in Outer Mongolia. Japan also had in Manchuria 150,000 to 200,000 troops.
The Imperial Army anticipated the German offensive, to commence in 1941-42. The Russians had to transfer several divisions from the Far East to European sectors, but the USSR would never leave Siberia defenseless, even if the war with Germany turned badly for her. It was thought to be almost beyond the realm of possibility for the Soviet Union to participate in a war between Japan and United States, of her own accord, thereby having to wage two-front operations. Certain reports mentioned the sending of 20 or 30 divisions to the European battlefront.
Although the Kantogun had been reinforced, the Russo-German War for which the Japanese Army had held such great expectations might not turn out favorably for Germany, despite Hitler’s boasts. A serious problem consequently demanded response: how could the expanded Kantogun pull through the rigorous cold of a Manchurian or Siberian winter? Military materiel was geared to hypothetical mobile operations against the Soviet Union, characterized by light weapons, large scale logistical systems, light armored groups and many horses. If after the southern operations are underway, the Soviet Army appeared to be mounting an invasion of Manchuria, requisite forces could be diverted there in ample time…
That Japanese were not going to attack the Soviet Union based on her bad experiences with the border conflicts, all else was typical ambitious war planning and speculation, but nothing was concrete. The Japanese Imperial Army was never serious about a conquest of the Soviet Union because they knew their limitations when facing armored forces on a broad front of an open plane, at least not without the Red Army being seriously disrupted by a German invasion that was sure to defeat them.