Cheat Mode:

At girl select screen, press A, A, B, Right, A, Left, B, Down, A, Up, then select any girl and start the game. From now on, by pressing the A Button you will be able to select any mahjong tile to add to your pool.

 

 

Hidden Copyright Screen:

In-game during the player's move on the second controller, press the sequence A, A, B, Right, A, Left, B, Down, A, and Up.