Both Final Fantasy XV (née Final Fantasy Versus XIII) and Kingdom Hearts 3 will release on Xbox One. Square Enix revealed both games at Sony's PS4 press conference last night, and officially added Microsoft's console to the lineup at its own E3 event today.
Kingdom Hearts 3 will be the first in its series to land on a Microsoft console--though portable titles like 358/2 Days and Dream Drop Distance appeared on Nintendo systems. The Final Fantasy series debuted on Xbox 360 with FFXIII.
Square Enix made a splash at Sony's conference, but nobody ever said they were exclusives. Stay tuned to GamesRadar for more E3 news as it happens.