To get 100000 Yen when you start a new game, have a Narutimate Hero 3 save on your memory card.
If you have a NH3 savegame on your memory card everyone except the following characters will be unlocked. This is how you get them.
To play as the stronger demon and kyubi forms (for some selected characters only), first unlock all the characters in the game (inluding the 4th Hokage). When in a character select sreen, do the ff:
If you have a NH3 save on your memory card you unlock all the characters except for Deidara, Sasori, Itachi, Kisame, Chiyo and the 4th Hokage.
In case you don't have a save game from "Naruto Hero 3" in your memory card, you can unlock secret characters by performing the stated tasks.