おい、君は本物の先生だったなあ。

True Sensei is a Black version on Sensei, He is Sensei's younger brothers nephew. He trains Ninjas the art of Ninja-Jitsu in the Ninja Hideout.

Background
His story begins a long time ago when Sensei was young, Sensei wasn't ready to show himself in public yet so True Sensei was ready to take over but his plan failed when he lost his black belt due to a giant accident. He went to Ninja Sanctuary to search inner peace and find his black belt. Unfourtunatly it didn't work and Sensei came to the Dojo. Ninjas were worried about him because they couldn't find him so they went to Ninja Sanctuary to find him, all they found was his black belt, ninja mask and sensei hat. They followed the trail and found him hiding, they explained that he was lost by many penguins so they got him to stay in the dojo but no one can see him because when he doesn't have his black belt, you disappear. You can still find him Practicing Ninja-Jitsu in Ninja Sanctuary.