One Piece: Grand Adventure
Unlock Eneru (Crocodile’s adventure mode):
Get Eneru as your ally in the Jaya area and win a battle using him.
Unlock Mihawk (Chaser’s adventure mode):
After recruiting Mihawk win a battle using him.
Unlock Mr. 2 Bon Clay (Crocodile’s adventure mode):
Get Mr. 2 as your ally and win a battle using him.
Unlock Nico Robin (Luffy’s adventure mode):
Get her as your ally at the end and win a battle using her.
Unlock Ohm (Crocodile’s adventure mode):
Get Ohm as your ally in the Jaya area and win a battle using him.
Unlock Shanks (Buggy’s adventure mode):
Recruit Shanks and then win a battle using him.
Unlock Trace (Buggy’s adventure mode):
Recruit him in Drum Island then win a battle using him.