Bought a cd/DVD in Japan, but says i cant watch it in the USA?

It's a region lock which is easily defeated. I am surprised more ex-pats don't even know this.

You don't have to buy another region free DVD player. If you have a PC DVD writer, you can copy the DVD and strip out that and any other junk the makers throw into it. There are 2 simple ways - the easiest is searching for a program like DVDFab HD Decrypter or DVDFab Free DVD at http://www.dvdfab.com/free.htm or you can get a program like AnyDVD, then rip your DVD to your hard drive and then burn it as a new DVD minus the junk. The paid versions you can use for so many days as a trial, which should suit your purposes.

When you put the DVD in your computer, you may have to accept the DVD writer changing its region code to read the disk. After that when you put in a US DVD you can change it back. Most writers allow up to 5 changes before it locks itself into a region permanently.

If you have a computer there is software that can override the region coding without the need to physically modify your dvd player's hardware. I use a North American laptop and watch region 2 Japanese dvd's just fine.

Research the "DVD43" plug in, works just fine for me.

DVDs have region code.

You can't play DVD you bought in Japan (region 2) on a player in US (region 1).

But you can play it on a computer with DVD drive.

The US is region 1, Japan is region 2. The only way around this is to get a region free DVD player.

Get a free program called VLC and load it to your computer and the disc will play. I use it on a Mac and play all dvds from all regions.

As Vinegar Taster said, it's a region code thing. It is possible to modify your player. Voids the warranty though. I've seen instructions on YouTube and other places. I expect the instructions are model specific.