Well, Helldivers started off as a downloadable-only title and is getting the physical treatment. Perhaps indie games that do superbly well eventually get a physical version some months later.Then again, Helldivers may just be an exception and I don't know any other indie game that has achieved this.Splatoon is the technical quality of an indie game anyway. The whole thing released around 1.5gigs. Production wise rocket league is every bit as good.
In terms of genre fps and soccer would be on pretty level pegging popularity wise in Japan.
Considering rocket league is a breakaway success, has a unique artstyle and is price quite low I can really see it selling well in Japan.
99% sure it won't be splatoon levels but it should still do very well. With the Baron release schedule between now and September it's a no Brainer.
Also a vita version could take off in Japan. Games like that are perfect for the vita.
