How to unlock all Naruto Ultimate Ninja Storm characters

Naruto Ultimate Ninja Storm screenshot

Take the following steps to unlock each of the 18 secret characters in Naruto Ultimate Ninja Storm.

1. Gaara: Complete “Burning Will Of Fire” in Flashback Mission: Leaf Destruction Arc.
2. Itachi Uchiha: Complete “Fatal Encounter” in Flashback Mission: Tsunade Search Arc.
3. Jiraiya: Complete “A Match With Pervy Sage”.
4. Kabuto Yakushi: Complete “A Whirling Rasengan Explodes” in Flashback Mission: Tsunade Search Arc.
5. Kakashi Hatake: Complete the Genin Training Arc.
6. Kankuro: Complete “The Aburame Clan” in Flashback Mission: Leaf Destruction Arc.
7. Kimimaro: Complete “Battle With The Sound Begins” in Flashback Mission: Sasuke Chase Arc.
8. Kimimaro (Curse Marked Second State): Complete “A Duel That Risks Their Bond” in Flashback Mission: Sasuke Chase Arc.
9. Kisame Hoshigaki: Complete “Toad Sage Shows His Ability” in Flashback Mission: Tsunade Search Arc.
10. Might Guy: Complete “Odd Beast Battles a Scourge” in Flashback Mission: Tsunade Search Arc.
11. Might Guy (Eight Gates): Complete “A Duel That Risks Their Bond” in Flashback Mission: Sasuke Chase Arc.
12. Naruto Uzumaki (Nine-Tailed Fox): Complete “A Duel That Risks Their Bond” in Flashback Mission: Sasuke Chase Arc.
13. Orochimaru: Complete “Sannin Rock Heaven And Earth” in Flashback Mission: Tsunade Search Arc.
14. Rock Lee (Eight Gates): Complete “A Duel That Risks Their Bond” in Flashback Mission: Sasuke Chase Arc.
15. Sasuke Uchiha (Curse Marked Second State): Complete “A Duel That Risks Their Bond” in Flashback Mission: Sasuke Chase Arc.
16. Temari: Complete “The Chunin Exam Sleeper Pick” in Flashback Mission: Leaf Destruction Arc.
17. The Third Hokage: Complete “Unprecedented Mega Battle” in Flashback Mission: Leaf Destruction Arc.
18. Tsunade: Complete “Tsunade Finally Opens Her Eyes” in Flashback Mission: Tsunade Search Arc.

Thanks again to Narutovshaku for sending in the list!