If you have a save file of 'Naruto - Gekitou Ninja Taisen! 2' present on your memory card you will start with an additional 20,000.
Also, if you have a save file of the original 'Naruto' game you will start with an additional 10,000.
By pressing the X button at the character selection screen you can choose a few different optional costumes for some characters:
Sakura:Long Hair
Ino:Long Hair
Sasuke:Blue outfit
Haku:Without Mask
To unlock the two-player survival you have to beat mission 24, get 15 wins in survival and unlock Mizuki.
Go to Anko's shop to purchase these fighters! They will have a Blue Icon with the Konoha (Swirl-looking) symbol