After entering Luca, it is announced that Blitzball is available to play. Blitzball is a completely optional mini-game. If you choose to play it is completely up to you, ignoring it will not take or add completion percentage. If you are familiar with it from Final Fantasy X, the game has changed. Players can still be recruited and are leveled up same as before. However, you now take on more of a side-lined coach role when the game is actually played. For more information about the game refer to the Blitzball page.
After learning about the game, head to the exit near Mi'ihen Highroad. Up the steps to the exit, across the ledge, you can open a chest with Light Curtain x3. From there, continue over to the balcony and a scene will be triggered. Yuna will discover a moogle that only she can see. Follow this moogle around Luca, past the stadium and to the docks. Along the way, Yuna will relive memories from Final Fantasy X. Follow the creature around until it stops at a ship. Yuna has one last memory and then Episode Complete is awarded.