I wouldn't say that they are racists, but speaking for another culture, you might say that they are appropriating that culture; that is, they are "taking (something) for one's own use, typically without the owner's permission". Appropriation assumes both that ownership exists, and that permission can be given. Personally, I don't find arguments for either points very convincing. One of the things that happens when cultures mix, is that they adopt aspects of each other, and both cultures change in irreversible ways. It's not always a comfortable process, particularly because one of the cultures typically has the socio-economic upper hand, but it is the same process that brought both of those cultures to the point at which they were right before they mixed. Kimonos aren't even originally Japanese. They were based on styles the Japanese adopted from the Chinese hanfu.