User blog comment:Wyvern 0m3g4/Feel Like Supporting a Cause?/@comment-3396538-20140415081234

Wikipedia's article on Jump Superstars explains simply why it is hard to get any J-Stars game outside of Japan.

"Jump Superstars will not be released outside of Japan on account of cross-licensing issues created due to the distribution rights of the several different series being held by numerous anime and manga licensing companies."