In story mode, there are certain characters you can control that are noticeable unavailable in versus mode. To unlock these characters, you must finish their three required levels, the last one being a boss fight. Some of these fights unlock two characters at once.
You can find the cheats screen in the options menu where you enter in the codes. These following codes are used for unlocking special swimsuit cards.
1. Go to versus
2. Life match, one life each. You can do 1 vs com or 1 vs 2
3. Choose Bridge stage
4. Repeatedly go to either side and jump off of the bridge, choose rematch
5. Every ten battles you earn a new Venue or Character