Feldgrau.net

...more than 70,000 Japanese troops joined the much smaller units of the Allied Expeditionary Force sent to Siberia in 1918....

Source

Japan War dead figure of 415 is from a 1991 history of the Japanese Army[19,111]. However, Michael Clodfelter reported the official toll was put at 300 KIA and noted that "A more reliable count of total Japanese military deaths from all causes lists 1,344 fatalities."[21] Casualties reported by the US War Dept in 1924 were 300 killed and died [25]

[ The Wiki table states 907 Japanese military were wounded in WWI.]
Source

Japan mobilised 800,000 men during World War I, of whom the Japanese reported approximately 300 were killed and 907 wounded, while 3 were captured or went missing, a casualty rate of only 0.2 percent. These figures do not include the 1,445 Japanese killed and 4,200 wounded at the siege of Qingdao [Tsingtao]. They may, however, have taken into account the 59 men lost when the Japanese destroyer Sakai was torpedoed while on excort duty in the Mediterranean. [ghp: I believe it was an Austro-Hungarian U-boat] The Siberian Expedition claimed another 3,116 dead, of whom 1,717 were from injuries and sickness, the rest from combat. Undoubtedly omitted are the 50,000 Japanese settlers abandoned in Eastern Siberia in 1922, many of whom died at the hands of the vengeful Bolsheviks....

Japan rejected French and Russian requests for troops to participate in land fighting against the Central Powers. Indeed, in January 1917, when Japan's allies again requested troops, Japanese diplomats at these talks demanded in compensation the northern half of Sakhalin Island, more control over railways in central Manchuria, and the demilitarization of Vladivostok, Russia's chief port....

Japan mobilised 800,000 men during World War I, of whom the Japanese reported approximately 300 were killed and 907 wounded, while 3 were captured or went missing, a casualty rate of only 0.2 percent. These figures do not include the 1,445 Japanese killed and 4,200 wounded at the siege of Qingdao [Tsingtao]. They may, however, have taken into account the 59 men lost when the Japanese destroyer Sakai was torpedoed while on excort duty in the Mediterranean. [ghp: I believe it was an Austro-Hungarian U-boat] The Siberian Expedition claimed another 3,116 dead, of whom 1,717 were from injuries and sickness, the rest from combat. Undoubtedly omitted are the 50,000 Japanese settlers abandoned in Eastern Siberia in 1922, many of whom died at the hands of the vengeful Bolsheviks....

Japan rejected French and Russian requests for troops to participate in land fighting against the Central Powers. Indeed, in January 1917, when Japan's allies again requested troops, Japanese diplomats at these talks demanded in compensation the northern half of Sakhalin Island, more control over railways in central Manchuria, and the demilitarization of Vladivostok, Russia's chief port....