This achievement is earned for having the following playable characters unlocked through either Story Mode play or accumulating a certain amount of Storm Points (SP):
Deidara-100,000SP
Kisame- 120,000SP
Sasori- 160,000SP
Hidan- 260,000SP
Kakuzu- 280,000SP
Itachi- 400,000SP
Konan- 480,000SP
Pain- 500,000SP
Once these character become unlocked and playable you'll unlock this 5G achievement!