There is a lot of slang to describe foreigners obscenely infatuated with Japanese culture, but these are the definite three most common terms:
An otaku is a Japanese geek, usually emerged in video games, collectibles, anime or manga or all of it.
A wapanese is derogatory for a foreigner who desperately wants to be Japanese, dress like a Japanese, speak like a Japanese.
A weeabo is a non-Japanese person who despises his own kin and culture and is shamelessly obsessed with everything Japanese.
