Eyeshield 21, Vol. 13: Who is the Real Eyeshield 21?

Could there be more than one Eyeshield 21? A player on a rival team claims he met the real Eyeshield 21 while he was an exchange student in America. Back then, this mysterious other Eyeshield was on the Notre Dame feeder school football team. But now he's in Japan, and he's going to play during the fall season!