You will need two (even three??) releases within in a year, though it all depends when they release the 3DS. This is what happens when you have that delay between the games and the Japanese releases. And the thing is that The Specter's Flute is a prequel to the series showing how Luke becomes the Professor's apprentice, setting the story for The Mask of the Miracle.
I though it could be interesting to think about the dates, because knowing this could help determine the release of the 3DS.







