Man, I forgot how the Fuji forest's OST in this game is bone chilling. Like this is based off of a real forest where people go to end it all. Fucking scary.
you need to beat the teams from the first game to unlock the area. They are scattered throughout the map. First you need to defeat Occult in Nara Park, then in the Northern Bridge you need to defeat another team, etc
if you want to recruit him too, go to this website watashiwa7.altervista.org/ie/2/recruit-cheat-codes-inazuma-eleven-2-npc.htm and search for the player you want. Then before you activate the cheat, go and talk to hillman to recruit any random player. then activate the cheat and go to the place you were supposed to meet the random player and you will see aiden