Episode Concluded is a status that can be achieved for certain areas of Final Fantasy X-2 in the last chapter, Chapter 5. This status indicates that the events for the area have come to a conclusion, but were not completed to the fullest possible level, which would have resulted in Episode Complete. If a player receives this status for an area, they may not receive certain special items or Garment Grids that can only be received by obtaining Episode Complete.
Additionally, getting an Episode Concluded for even one area means that the player will not receive the Mascot dressphere. In general, Episode Concluded is something most players would likely avoid, though dedicated players might wish to explore it, as it sometimes offers alternate scenes and additional dialogue that shed new light on the characters.
Additionally, pinning either Rin or Prophet for the Mi'ihen Highroad mystery will result in Episode Concluded status. Pinning Rin is the only way to obtain Gippal's Sphere, whereas pinning Prophet does not grant the player any special item, but does result in a highly amusing scene.
Whereas it is possible to obtain Episode Complete for every area within Final Fantasy X-2, certain areas do not qualify for Episode Concluded - completing events in those areas will always result in Episode Complete. Those areas are Mushroom Rock Road, Djose Temple, Calm Lands, Thunder Plains, and Bikanel Desert.