XIII機関
The concept of the Organization was originally introduced in "Kingdom Hearts Final Mix" within a bonus ending titled "Another Side, Another Story [deep dive]", where their Japanese name was translated as the "Thirteenth Order". The group was later introduced as the "Organization" in the game ', where they serve as the main antagonists, and returns in the same role in "Kingdom Hearts II". Organization XIII is prominently featured in "Kingdom Hearts 358/2 Days" as characters available for play, along with a new female member named Xion. Several members, prior to becoming Nobodies, appear in "Kingdom Hearts Birth by Sleep", return following their restoration in ', and have returned in "Kingdom Hearts III".