While there were some differences, the aggressive actions by these two countries in the years leading up to World War II were essentially the same. They were both essentially driven by a desire to upset the status quo and to gain more power for themselves.
It is true, of course, that Germany was a loser in World War I while Japan was a winner. However, they were both unhappy with the status quo after that war. Germany was unhappy because it had had its empire taken away and because it had been humiliated and weakened in a multitude of ways by the Treaty of Versailles. Germany engaged in aggression because it wanted to be seen as a first-rate power. Japan was unhappy because it lacked what was, in its eyes, a sufficient empire. It felt that it should have more power in its region when, instead, European countries held Asian colonies such as Indochina and Indonesia. It engaged in aggression because it wanted to be seen as the dominant power in its region.
Germany’s aggression did have more of a racial element to it. However, the Japanese did also see themselves as superior to the peoples they conquered. Japan was not interested in genocide, but it did believe that its people deserved to be the lords of their region.
In these ways, the aggressive actions that these two countries took before WWII were essentially similar.