Thanks for the feedback guys.
@ extepan: That's really good to know, if it's true. I wish I could read the original article too. My only problem is that, as I said, the packaging of the overseas versions has print on it reading very blatantly that the sale of those products is prohibited in Japan. Whether or not this includes legal importing of the products, I don't know. That's why I'm wary.
@ nmskalmn: Well, I'm not going to Japan any time soon, I'm looking at things in the long run at the moment. I plan on going there for at least a relatively lengthly span of time at one point, and I would like to have my whole collection with me...which is rather large. My Ayumi collection alone is 15 CDs, only 6 of which are Japan versions, and I don't have many other Japan versions besides those. My total collection...well, plus the 9 Ayumi CDs that are overseas, I think I have around another 18 that are overseas ones (and then also the Japanese versions, and then some of the domestically released ones that I'm not too concerned with). If I wanted to bring everything with me, something tells me I'd probably have a problem.
@ T-Z333: That's true, but having just so many CDs with me might catch a lot of attention. Unless...I could bring a certain amount with me and then have a friend send me the rest of mine in the mail.
Thanks again for the input everyone!