In the North American/Worldwide versions of the game, you can unlock Maniac charts by completing all Trick charts. However, the Japanese version of the game which released first contained a much more convoluted two-part process for unlocking Maniac charts that went undiscovered for several years and was previously only thought to be accessible through GameShark cheats:

• The first part involves highlighting several songs in a specific order for very brief seconds:
1. Highlight "Mickey Mouse March (Eurobeat Ver)" for 1 second by coming from the song to the left of it
2. "Chim Chim Cher-ee" for 2 seconds from the left
3. "Macho Duck" for 1 second from the right
4. "ELECTRICAL PARADE (Radio Future MIX)" for 1 second from the left
5. "IT'S A SMALL WORLD" for 2 seconds from the right
6. "I Want You Back" for 1 second from the right

The first song, "Mickey Mouse March (Eurobeat Ver)", must be selected by coming from the left, which means you must immediately move to the song to the left when the song select screen loads. The songs do not count towards unlocking Maniac charts until at least roughly a second passes, so there is some wiggle room to correct mistakes. If you succeed with the first part of this process, then you will not need to redo it should you mess up the second part.

• The second part requires plugging in a second controller and inputting several button combinations on both controllers (P1 = first controller; P2 = second controller):
1. Press Down on the D-Pad twice to select Trick mode
2. Press P1 Triangle and P1 Cross
3. While still holding P1 Triangle, press P1 Cross again
4. Press P1 Square and P1 Right
5. While still holding P1 Right, press P1 Cross
6. While still holding P1 Cross, press P2 Square
7. While still holding P2 Square, press P2 Triangle
8. While still holding P2 Triangle, press P2 Cross
9. While still holding P2 Triangle, press P2 Right
10. Press P2 Cross and P2 Square
11. While still holding P2 Square, press P2 Right
12. While still holding P2 Square, press P2 Triangle
13. Press P2 Cross and P2 Right
14. While still holding P2 Cross, press P2 Square
15. While still holding P2 Square, press P2 Right
16. Press P2 Triangle and P2 Cross
17. Press P2 Square and P2 Right

Should this code be inputted correctly, a ding sound effect will be heard, and Maniac mode will be selected automatically and can be reselected whenever you want without inputting the code again.