Someone who pretends to know Japanese and chases after pretty girls yelling random gayass things.
Also see faggot-san.
Japanese Fanboy: KONNICHIWA SHIVA-CHAN!!! AISHITERU!!! KAWAII DESU, NE????
Shiva: Go away you fag!
Japanese Fanboy: ...*crycrycry* I'm going back to my Anime-Con!
ChillinHotdog006: LMSAO XD
^the second definiton of Sushi-san