Ok just an hour ago after school I found a Japanese Pokemon Stadium for N64(basically this is our Pokemon Stadium 0 because it never came out of Japan). For a Japanese game that is priced $15 is not that bad. It took me by surprise that I found a Japanese game in a PAWN shop here in the U.S.. So my question is can I play Japanese N64 games on a NA 64 system?
From what I understand, Japanese N64 cartridges do not have chip lockouts however are built in a different shape from other regions so they can't be used. When I looked it up I got mixed responses on it though x: .
Apparently you need something like Gameshark to use JPN games on another N64, but looks like you can play them on there once you have it. Good luck.
What I'm getting from a quick search is that NTSC-J (Japan) and NTSC-U (USA) are region locked physically. So if you live in the US then it is a matter of just getting it to fit (this can be modding the system, the cartridge, or using an adapter). PAL (Europe) systems however are not directly compatible with either NTSC forcing you to use a specialized adapter called a "Passport" to make it work. These however are expensive and rare enough that you might as well import an NTSC system. Disclaimer: That was based off a quick Google search, I've never owned an N64 so I don't have any first hand experience on this subject.