Yu-Gi-Oh¡ World Championshi 2010 Reverse of Arcadia i need help

i have beat the game and continue but i don't know how to unlock a tag partner to play tag duels in story mode, i already know how to unlock them in World Championship mode, but no in story mode.there is another ting about this game, in the underground arena, ther is a guy who want duel akiza, but i go to talk to akiza and noting happens, what i need to do?

http://www.gamefaqs.com/portable/ds/code/978594.html

each duelist have their pair correspondingly.... try search for the pairs or go to link stated by biomon

ok i'll try.