[Hazuki]

The DVDs from Japan have a different code from the ones in USA.

The best you can do is buy a cheap DVD player, or a region free one.
The one I use was cheap (10~15$) and you can change the regions.
I'll give you the name of mine and how to change
since region free DVD player are kind of EXPENSIVE.

MODEL: Daenyx DV2001
01- Open the tray
02- Open the MENU
03- Press the numbers on the remote: 9735
04- A number should appear on the right top,
then use the up or down buttons to change the region.

For your DVD, it should be either 2 or 3, you can check at the back of the CD case

[EDIT] I just checked on the internet the price of this Daenyx DV2001,
it seems to be 25$ in some places, I guess mine was on sale?
Though it's worth it to me~