NINJA BLADE

There are 20 outfits. Some need to be collected in the levels, and some are given as reward when you complete many conditions through the game.

1. Standart Oufit
2. Pin Stripe : hidden in level 1. When you learn to jump during wallrunning, drop down, and there is a wall to break : outfit is behind it.
3. Sword and Moon : unlocked by finishing Mission 1 in less than 30 minutes.
4. Pine and Crane : hidden in level 2. When you enter a dark room with a giant plant to burn, the oufit is behind a breakable wall right hand of the plant.
5. Lion Dance : Unlocked by performing 20+ Finish Attacks in mission 2.
6. Hearts : hidden in mission 3 behind a breakable wall just before the last boss battles (before dropping on the bus wrecks).
7. Kurokawa Yakuza : Unlocked by getting a Hit Count of 30+ in mission 3.
8. Clown : Gained during mission 4, in the plane, when you have to break all the crates to maintain altitude. The outfit in it one of the crates.
9. Ninja : Unlocked by finishing mission 4 with less than 30% damage on the Jet's Health bar.
10. Camouflage : hidden behind a breakable wall in mission 5, in the big room with leaking steam (before the second blastmite boss fight).
11. Endless Flowers : Unlocked by beating mission 5 within 40 minutes.
12. Moon : In mission 6, after the elevator cutscene, the outfit is hidden behind you in a crate.
13. Evil : Unlocked by finishing mission 6 with 10+ combo kill.
14. Chrysanthemum and Chalice : In mission 7, on your way to the fire shuriken, you can grapple to a higher platform blocked by a fire. Outfit is on this platform.
15. Warrior's Creed : Unlocked by finishing mission 7 within 50 minutes.
16. Cherry Blossom : in mission 8, hidden on the first platform you fight on, in a barrel.
17. Love : unlocked by beating mission 8 with less than 1000 points of damage taken.
18. Maple : in mission 9, after beating the first big boss, take the left pass at the fork until you arrive at a leaking steam area and two breakable walls in a row. Continue your way the opposite side of the slime chopper and you'll see another breakable wall near red barrels, with outfit behind it.
19. Invincible : unlocked by beating mission 9 without Retry.
20. Ninja Blade : unlocked by getting Overall Score A+.

You might have to do the mission 9 again to unlock the Ninja Blade outfit (even if you already have the A+ ranking and if it's the last mission you did), and the achievement.