Mistaken for a Japanese?

Do I look like this? :-)

A close friend recommended a teaching job to a student in Seoul, Korea. I was excited since it means additional income and since it's done online, I won't have to travel and be in Seoul every time we're having class. The first meeting went fine. As usual, we had introduction, agreed on time and set our expectations. She wanted to use a book which I don't have, so my friend suggested that I should buy one in a Korean shop called, Koreana. I went there immediately and looking the people inside I could tell that they were Koreans including the cashier. I saw the book that I needed, New Interchange 1, but because I was not blessed with height I couldn't reach for it. I was looking for a chair or something which could make me taller, but I unfortunately I didn't find one. So I needed someone's help from the store. I turned to the other shelves and saw a Korean looking man, so I asked him politely.
"Excuse me, could you get me one New Interchange book please?" I pointed the shelf where it was displayed.
He didn't say anything and just followed. He easily reached the book because he is tall. He got the wrong book, so I told him to change it. He asked me which color I like, I said I wanted the blue one. He handed the book and thinking that he was the owner, I asked him again,
"How much is this book?" He just smiled and said, "I'm sorry I don't know" then added,
"Well, I'm also a customer here".
I was a little embarrassed because I thought he was the owner of the store, so I immediately thanked him and went to the cashier.
While at the cashier, I asked the Korean looking woman for the price. I handed her the payment which is P500. She asked if I had a smaller bill, in our Cebuano dialect. I thought she was a Korean woman, but she spoke Cebuano perfectly. So that's alright, my mistake number two. I gave her some smaller bills then when I turned around I saw the man, and smiling he said in our dialect.
"Oh my god! you gave me a hard time speaking English earlier, I thought you're a Japanese so I answered in English!" "What is this book for? are you going to study Korean?" he inquired.
He still had other questions but I said I must go ahead since I still have a class, which was a lie. He and his other friends were laughing when I left the store..this is my Korean shop blooper.