The meaning could be someone from a different culture that has no interest in there own or another's aside for a someone with a Japanese background. They usually mix Japanese words in with English sentence and refuse most things non-Japanese.
Wapanese are big fans when it comes to cosplaying but so are anime-fans. There's a difference, anime-fans are creative, original and have fun with cosplaying. Wapanese on the other hand take it seriously and criticizer even particularly good cosplayers.
Again, just because one buys untranslated anime doesn't mean there wapanese. I myself have been sent Chinese anime from relatives in China. I watch it big deal. A wapanese will use untranslated anime as a way to learn Japanese.
I'm Chinese and proud, be like me and show your culture!
P.S AGAIN JUST BECAUSE YOU LIKE ANIME DOESN'T CONSIDER YOU WAPANESE!