So basically, we can have Japan go through the turmoil I explained earlier, and then use the Red Prince (I'm liking this name) to support socialism and then use his influence with the military to support a civil revolution. Is that enough to defeat the financial elite? It seems that the latter would be doing all they can to get rid of the Red Prince in this case. Perhaps he would get vocal about his positions, be interpreted by his enemies to be the centerpiece of the revolutionary movement, be assassinated, and then turned into a martyr?
It seems like I need to know more about the general situation regarding Japan's ruling structure, in addition to the formation of indigenous Marxism. If we want to create a Japanese Lenin, is it imperative that he is of the royal family or is it possible for him to simply be some outspoken scholar or the rebellious son of a wealthy family?
EDIT: On further consideration, it seems that Prince Chichibu might be a little bit late if the revolution is to happen in the late 1920s. Are there any individuals who could take his place?