Confused

Hey guys. I have like this one guy since the sixth grade and we were talking today and I was asking him if he had a girlfriend and he said uh no. I asked do you like anybody. He told she was an exchange student from a small town in japan. I have friends who are exchange students from the same town. So I asked him what's her last name. He said he didn't know and told me to calm down and asked me why I was asking. So I explained to him and he replied i was making her up. I asked why and this was his exact reply "CUZ personal information" this scared me given he's my best friend and I had never seen him respond like that. Now idk if he knows I like him but all things aside I'm worried about him. He tells me everything. Any ideas on how to approach this.