Why were the Japanese so violent in World War 1?

It seems there may be a misunderstanding; Japan was not particularly known for violence in World War I. In fact, Japan joined the Allies and primarily sought to expand its influence in Asia, particularly by seizing German territories in the Pacific and China. The perception of Japanese violence is more associated with World War II, where militarism, nationalism, and imperial ambitions led to aggressive actions in China and the Pacific.