This patch unlocks all 5 hidden characters (Super Saiyan versions of Trunks, Gohan, Goku and Vegeta and the Perfect form of Cell).
It is in ips format and can be applied to both the French and Japanese versions of the game.
Thanks to
http://www.romhacking.net/forum/index.php?topic=27795 for the request and cheat codes.
NTSC-J CRC32: 8C7780BD
PAL CRC32: EA7ABAD1