Originally Posted by Sharky

Well, it was released in Japan, just not to the general public. In other words, it was never sold in stores and it was never in print for very long.

Subscribers of Weekly Shonen Jump could get it on either VHS or DVD if they sent in a special coupon included in that weeks issue. Shonen Jump would then send back a copy of the special. This is the only way (outside of someone then re-selling it) for fans to get it.

It's never been shown on TV in Japan.

It may have already aired on Cartoon Network in the USA. I could be wrong on that though. I don't have a working TV at the moment (nor do I have the USA version of Cartoon Network), so I can't say for sure. I do remember seeing on some website like Toon Zone that a "Naruto Special" would be airing a while back. I don't know if this was simply 2+ episodes put together, or an actual OVA.

I've also seen Shibuki on one/some of the VIZ CCG cards, so this would further backup the idea that it's already aired in the USA. Putting a character from an "episode" that hasn't even released yet seems a bit odd.