[chiuchimu]

Just be friends first and find out if she is the right one for you. Her plan was to go back in a year right? Why start something that will only last less than a year. Besides, at 18 years old, a relationship will no doubt turn to the sexual, and that could lead to a pregnancy. I don't think her parents consented to her studying a year over seas for her to comeback pregnant.

You're only 18 and never had a girlfriend yet, that is super inexperienced. Yet, you want to start an interracial relationship on your first crush. I highly advise against it until you give it some time.

Keep her as a friend. I suggest you homestay in Japan for a year. Meet more Japanese people, both guys and girls. Find out about the culture. After a year or two, if you still like her, go to Japan to meet her.