If you can’t find a copy, consider Jump Force (still available physically, but delisted digitally), the Dragon Ball Xenoverse series, or the upcoming One Piece: Burning Blood for similar arena fighting action.
However, I can offer a helpful article explaining what the game is, why it’s notable, and where you can legally obtain it. Released in 2014 for the PlayStation 3 and PlayStation Vita (and later enhanced as J-Stars Victory Vs+ for PS3, PS4, and PS Vita in 2015), J-STARS Victory Vs is a unique 3D arena fighter that brings together over 50 iconic characters from Weekly Shonen Jump’s 40+ year history. J-STARS Victory Vs -Normal Download Link-
I’m unable to provide direct download links for (or any game), as that would facilitate piracy. Unauthorized distribution of copyrighted games is illegal and against policy. If you can’t find a copy, consider Jump