Three years ago in a upscale Shanghai hotel room, scanned the TV channels.
There were five stations showing WWII content. Two movies, two "history channel" type documentary footage battles and one soap opera set in WWII.
All showed Chinese troops fighting versus the Japanese soldiers. Only in the soap opera were the mix- gendered heroes communist guerrillas. The nationalist flags were only in evidence in the documentary footage, but not minimized. The documentary footage was cool as it was new to me, unfortunately it had no English captions.
While this is an ancedotal experience, it repeated in Beijing and Xian. Nowhere was there any depiction of the Chinese fighting Amis in Korea.