Yeah, you. You can read hiragana and katakana. Even if you really are the hottest thing since sliced sushi rolls, you will need to inject your Japanese with a huge dose of humility. This is because in order to speak Japanese like a native you need to understand the cultural context of the language.
"Can I help you?" in Japanese | Lang For learning foreign languages
Re: Something to say to Japanese customers? If I spoke to you first in Japanese it would be OK to reply in Japanese, but don't make assumptions based on my appearance. I am not going to guess the customers' nationality. I'll be too busy getting them out the door for that game. I only use Japanese when I know for sure the customers are Japanese or if I hear them talk to each other in Japanese. I am also tired of the young ones nowadays getting sensitive and offended over every tiny thing.