Naruto Easter Egg
In Case 2: Monsterous Turnabout, you may spot references to "Nine-Tails" and people will make comments to the order of "It was sealed away" and "It caused devastation." The nine-tailed beast also does bear more than a passing resemblance to Nine-Tails, the character from Naruto.
Phoenix's 'Nostalgic' Outfit
By completing the Downloadable Content episode; Turnabout Reclaimed,you will be given Phoenix's "Nostalgic" outfit to wear in-game. This is the same outfit that Phoenix wore briefly in the Third game in the series: Trials and Tribulations.