In Ninja Launcher, or StreetPass Ninja for PAL users. You are being launched from a cannon to stop demons from unleashing chaos over the world. Using scrolls, which are earned by StreetPass, those scrolls upgrade your weapon and uniform to challenge those demons. The more scrolls you get, the more powerful you become.

StreetPassing any Mii will get you a scroll to upgrade your Mii. Get all the scrolls on a level for a perfect, which doubles your attack. Some levels require that you get a certain amount of scrolls to beat those monsters since most often, they strike first before you do. If you fail to have one of your armors strong enough to stop the demons from attacking you, you are forced to retreat without dealing any damage. Gathering many allies is necessary for progressing smoothly.

When you StreetPass a Mii, you get a scroll. I do not know exactly if a Mii's favorite color represents the type of scroll you would get, but the Mii's height may play a factor in this game. The smaller the Mii, the closer the scroll is from the cannon. And the tallest is the farthest and the last to collect. Special Miis don't do anything unique as far as I know.

Edit: A Mii's favorite color does determine the type of scroll you get. Thank you @guiraudwilliam5545 for confirming this.

This is the sixth and final part of the playthrough. This concludes yet another StreetPass game. Here are the timestamps.

0:18 61 (Skeletal Supreme Warlord)

3:36 62 (Tengu Supreme Warlord)

6:38 63 (Oni Supreme Warlord)

9:48 64 (Armored Supreme Warlord)

12:55 65 (Mechanical Shogun)

16:01 Ending

16:39 Staff Credits

18:55 Checking Collected Medals