I grew up in a very Filipino and Japanese area with some Korean and Chinese here and there. You kind of learn to distinguish the difference between them based on the way they talk and just by face. Although there are those few that are a bit difficult to tell apart.

I'll have to agree with the post above about Japanese being friendly people. Japanese and Filipinos are friendly people. Especially Filipinos, of all the Asian/pacific islander cultures I'd have to say Filipinos in general are the most open to other cultures.