One could say that the mere existence of The World Ends With You characters in Kingdom Hearts 3D: Dream Drop Distance is enough of a tease, but Kingdom Hearts director and zipper-obsessed character designer Tetsuya Nomura hints at something more than that.
The primary hint is about as subtle as a ten-ton hammer. In an interview, Nomura said, "Regarding The World Ends With You, I can't say anything at present… (laughs). But there probably is something."
That would just about seem to seal the deal, but there's more. While talking about The World Ends With You characters in Kingdom Hearts, the subject turned to Rhyme, who had no lines in TWEWY other than reaction voices. In KH3D, however, Nomura and co. opted to cast a voice actor for Rhyme "out of consideration for the future of The World Ends With You series."
Sounds like we have more The World Ends With You to look forward to at some point down the road. Anyone excited to revisit these characters outside of their upcoming Kingdom Hearts appearance?