Taisen route

A Challenge Route (エクストラ対戦ルート), also known as Extra Root Competition, is a game mechanism that exist since the first game. It's a system where you confront various teams following a route, where at the end you can gain items based on your rank in the previous matches. Also, after the matches you can get Drop Items.

Until Inazuma Eleven 3 it was a way to recruit characters that you meet along the game's main story course. From Inazuma Eleven GO onwards, it function changed, so you'll need to beat a specific team until a Kizuna Item drop from it.

Ranks
After you beat a team, you can get one of these ranks based on how good you are:
 * B: Score two or less goals of diference.
 * A: Score three or more goals of diference.
 * S: Score five or more goals without losing one.