Infilitrate the score rankings:
First start a league and after a game, save the league. Next, when you can see the score rankings remember those players and press reset. Then go to the option mode trade screen and trade those players with anyone you want. Then press reset(not the one on the machine) and cancel that trade. Then go to the saved league and check the score rankings. It should be changed.

Two Additional New Teams:
Perfect Striker contains two additional, hidden teams. There are two ways that you can get these two new teams: 1.Play through and beat the league mode. 2.Enter the following code (at the title screen): Up, L, Up, L, Down, L, Down, L, Left, R, Right, R, Left, R, Right, R, B, A, and then hold down Z and press Start.