This page lists how to unlock all the characters in One Piece: Pirate Warriors 2 (Kaizoku Musou 2)

Character Type Requirements
Luffy Attacker start the game
Zoro Attacker Act 3-6
Nami Technical Prologue-2
Usopp Technical Act 3-4
Sanji Attacker Act 3-6
Chopper Technical Act 1-3
Robin Technical Act 3-4
Franky Attacker Act 1-1
Brook Technical Act 1-3
Smoker Technical Prologue-2
Jimbei Attacker Act 1-2
Marco Attacker Act 1-4
Kuzan (Aokiji) Technical Act 2-1
Perona Technical Act 2-2
Hancock Attacker Act 2-3
Ace Attacker Act 2-4
Kuma Technical Act 3-1
Mihawk Attacker Act 3-2
Crocodile Technical Act 3-3
Buggy Technical Act 3-5
Garp Attacker Act 4-1
Whitebeard Attacker Act 4-2, Whitebeard Rescue mission (see "True Ending" sheet)
Law Technical Act 4-2, Whitebeard Rescue mission
Kizaru Attacker Final Act-1
Eneru Technical Final Act-1
Akainu Attacker Final Act-2
Blackbeard Technical Final Act-2
Pre-skip Straw Hats After Final Act, complete each member's pre-skip episode
Blackbeard (double power) Blackbeard's partner episode, plus all pre-skip SH episodes?