Aside from the name there are several somewhat significant changes between the US and JP releases.

1. From the start all gates are unlocked in NTSC-J which means you will be able to finish the game faster by default
2. There is no stat upgrade screen in NTSC-J, all characters are unique and stat locked.
3. All licensed music was removed so no Less than jake, no Pietasters, and no ALL. At least your vods wont get muted or flagged on YT.

Alternate Japanese release of the USA version: [The Skateboard: Simple 1500 Vol. 47]: This was a budget release in Japan they simply ported the USA version with all the licesenced music and course changes in the US version back to japan for a cheap price. Runs submitted with this version will be ranked with Street Sk8er since thats literally what it is.

So from all my testing I think the NTSC-J release is almost minute faster for 1-loop just by not having the stat screen. And having all routes unlocked from the beginning makes it different enough for me to create its own category.