For 1 4 months after release Ryu Ga Gotoku Ishin will be available to be upgraded from the PS3 to the PS4 version through the PSN for only ¥1000 (Roughly $9.99 USD).
Not a bad deal for users who want to buy and plan on getting a PS4 later. Much like our western games upgraders will need to keep the PS3 disk to be able to launch the upgrade version in their PS4 consoles.