Small question about Oscar in Tokyo
So I watched the movie last night, found it really cool, but there's one trivial thing I keep coming back to. At one point in the film, we find out that Oscar's parents said they'd take him and his sister to Japan one day. So his desire to travel to Japan makes sense. But do we ever get any explanation as to when exactly he traveled there, or how he got there?
I know it doesn't matter much, just wondering if I missed something.