I'm not an expert on the era, and I'm a bit confused by a couple ostensibly conflicting events:
Mostly, I'm confused by the comfort of people like Sun Yat-Sen and Qiu Jin with Japan, when Japan had just tried to invade China. The Tongmenghui were obviously no big fans of the Qing, so was it a "enemy of my enemy is my friend" sort of situation? So much of my understanding of Sino-Japanese relations is colored by the Rape of Nanking that I don't really know much of how the two nations viewed each other before that.
Thank you!
I'll have to leave the rest to people more knowledgeable about prewar China, but:
when Japan had just tried to invade China
The First Sino-Japanese War wasn't an invasion of China; it was a successful Japanese attempt to remove Korea from the Chinese sphere of influence and place it within the Japanese sphere.