Hello there! Japan's respectful treatment of Russian prisoners of war might be characterized as a "civilized façade," since they failed to apply the same standard to the Chinese during the First Sino-Japanese War of 1894-1895. To be sure, in September 1894 War Minister Ōyama Iwao reminded the Army that Japanese soldiers "must never forget that however cruel and vindictive the foe may allow himself, he must nevertheless be treated in accordance with the acknowledged rules of civilization..." Ōyama also emphasized that civilians were to be protected. A few days later, he articulated: "Our Army fights for the right and in accordance with the principles of civilization. Our enemies are the military forces of the country with which we are at war, not the individuals of the country. Against the force of our foe we must fight with all resolution, but as soon as any of his soldiers surrender, are taken prisoners, or receive wounds, they cease to be enemies, and it becomes our duty to treat them with all kindness." Japan, it other words, would uphold its obligations as a signatory of the 1864 Geneva Convention. [1]

Yet Ōyama's orders did not stop the massacre of Chinese prisoners of war and civilians at Port Arthur starting on November 21. The wanton violence shocked foreign reporters--the New York World claimed wildly that Japanese troops had slaughtered as many 60,000 Chinese in a span of four days--and quickly created a public relations crisis for Japan. On December 16, in an effort to control the damage, the Foreign Ministry issued a statement: "The Japanese Government desires no concealment of the events at Port Arthur. On the contrary, it is investigating rigidly for the purpose of fixing the exact responsibility and is taking measures essential to the reputation of the empire." According to their own description of events, Japanese troops, "exasperated by the wholesale attempts [by Chinese soldiers] to escape disguised as citizens," had regrettably "inflicted vengeance without discrimination." The Foreign Ministry then criticized "exaggerations" by foreign media, insisting that "the victims, almost without exception, were soldiers wearing the stolen clothes of citizens." In all likelihood, however, many Japanese had already begun to view the Chinese as racial inferiors. The government also failed to initiate a formal inquiry in order to avoid implicating senior officers. [2] The Port Arthur Massacre disturbingly paralleled what would happen in Nanjing several decades later.

Japanese forces would ultimately take few prisoners in the course of the conflict. There was a clear double standard; after sinking the British-flagged troop transport Kowshing on July 25, 1894, sailors of the Imperial Japanese Navy rescued European crewmen who had abandoned the ship--but not the drowning Chinese. Having learned from their experiences in the First Sino-Japanese War, during the Russo-Japanese War and First World War the government would improve its image among Western powers through the sterling treatment of prisoners of war. But by the time of the Second World War, when Japan's ambitions had shifted and when their propaganda emphasized the superiority of the "Yamato race," not even Westerners deserved sympathy. [3]

[1] S. C. M. Paine, The Sino-Japanese War of 1894-1895: Perceptions, Power, and Primacy (Cambridge: Cambridge University Press, 2003), 209f.

[2] Ibid., 214; Edward J Drea, Japan's Imperial Army: Its Rise and Fall, 1853-1945 (Lawrence: University Press of Kansas, 2009), 86f.

[3] See Rotem Kowner, "Imperial Japan and Its POWs: The Dilemma of Humaneness and National Identity," in War and Militarism in Modern Japan: Issues of History and Identity, ed. Guy Podoler (Folkestone: Global Oriental, 2009), 80-110.

There was a fundamental shift in Japan's behavior in between the wars. They went from trying to be seen as a western style great power, to an east Asian power that would liberate all the oppressed east Asian nations. Also, the late 20's witnessed the end of a period of Japanese history called "Taisho democracy", after this period military leaders became more influential and Japan became very militarized and authoritarian. This shift towards a fascist dictatorship was led by Sadao Araki. This new Japan focused on expansion and "liberation" of the oppressed Asian nations. The Japanese instituted a racial superiority doctrine. The role of the Japanese as the greatest and purist race was emphasized, other races were deemed inferior. The Chinese specifically were seen as little better than pests or vermin and this was a major reason for the Japanese treatment of the Chinese.

source:

Japan's Imperial Army: Its rise and fall by: Edward Drea

A History of Japan L.M.Cullen

I would like to suggest reading this book along with the other fantastic things already recommended: Hidden Horrors: Japanese War Crimes in World War II by Yuki Tanaka. Tanaka tackles some of the biggest issues of Japanese atrocities committed during WWII and examines the shift in Japanese culture from the early twentieth century to when the militarists took control of the Japanese government in the 1930s. I just finished reading it for an East Asia class I'm taking right now. The book is very helpful.