Whoever this may be, the MF5 product page states that the person will be voicing the protagonist in the promo anime, and possibly even the game (if I got the translation right).

In any case, the site also states that pre-ordering the game will net you a DVD of the anime. There're still a few tidbits I couldn't get, though, including something about that one golden Piroro.

https://www.tecmo.co.jp/product/mf5/cpgn.htm

All I could find was that he did something in Super Monkey Ball 2, by Sega.

Hey, whatever works.

Furthermore, thanks to Lisa, I can confirm that the anime DVD, available as a pre-order bonus, can be used to generate a special Piroro breed.

I get the feeling it will be named Pyro stateside.