This game is different from all the other, because while still connected to the Kingdom hearts Story line, this game features Roxas as the Main Character. The game Survey's Roxas's life before the organization. It's also TWO players (Fancy that!).
The game focuses on the Daily Life of the Organization, The name 358/2 Will make it's self known apparently when you beat the game. It focuses on How long Roxas was in the Organization and his battle with Riku.
IT drops May 30th in Japan Only lol
For more info