I checked what happened between Japan and China this decade, and I saw that relations warmed and it was a prosperous era of trade and cooperation.

That's good enough for me. What the little "people" in China think of Japan IRL has little to do with how I'll roleplay this game. Besides, if I am a slave to history, this game will get boring. Since I'm actually being within a degree or two or reality, I think I'm good.