User blog comment:Naty Ranmaru Sawada/Inazuma Eleven GO Galaxy Supernova/Big Bang Recruitments/@comment-24529314-20140317074919/@comment-4485900-20140319160659

You can recruit them at the Comm. Master in the Holy Road Stadium, and you'll first need to recruit at least 5 (or 10) players in that Comm. in order to make them available.

As for the detailed conditions for each player, well sadly I don't remember.