When I purchased my japanese knife from Korin, I remember reading on their website: Do not use a sharpening steel to sharpen your Japanese knife. Using a sharpening steel can damage your blade and change the body style of your knife. (Source: Knife Care)
In fact if I remember correctly, someone here (I believe it was Chris Lehrer) explained to me that the Japanese knives' steel was harder than the European's, and using a steel might break the edge rather than bring it back in place. I hope I understood correctly.
However, I keep hearing (or reading) some people recommending steels seemingly without any concern for whether the person uses a japanese or european knife. In fact some japanese knife companies (i.e. Shun) make and sell steels.
By the way I own a Togiharu inox steel 9.4" and a King 1,000 stone.
So what about you, do you steel your Japanese knives?