NTSC-J game PROBLEM... Please Help me!

Guys, i need some help.... i downloaded All star japan pro wrestling III ;D, to ps2 but i wasn't able to play it :( cuz my ps2 is NTSC-U/C i think(it is in its box) and the game is japanese:P, NTSC-J. I didn't thought that i would have this kind of problem cuz my ps2 is unblocked with infinity matrix v1.4 chipstet, and since i bought it, I'm able to play PAL games with no problems...Please...there is some way to make my ps2 run the game? or convert the game to NTSC? I googled my problem but i don't find the solutions... :-\
I'm want to play this game SO BAD :'(
Thanks Guys :)

NTSC-U and NTSC-J are incompatible variants of the same standard. You will not be able to convert.

...is this ps2 modded at all like a mod chip or disc swapping?My chipped ps2 runs Pal (my region), nstc and nstc-j just fine.Modbo...something XD