After fulfilling the requirements to unlock a character, their mark will appear in the Kuchiyose menu. Select their mark and copy it onto the grid on the bottom screen using the stylus, taking care to use the proper stroke order. Correctly drawing a character's mark will unlock them, even if their mark hasn't been acquired.

Unlockable	How to Unlock
Deidara	Complete Arcade Mode with Itachi
Fukusaku & Shima	Complete Arcade Mode with all characters
Itachi	Complete Story Mode
Jiraiya	Complete Arcade Mode with Naruto
Jugo	Complete Arcade Mode with Karin
Karin	Complete Arcade Mode with Suigetsu
Konan	Complete Arcade Mode with Jiraiya
Orochimaru	Complete Arcade Mode with Jugo
Pain	Complete Arcade Mode with Konan
Suigetsu	Complete Arcade Mode with Sasuke