Voiced by: George Takei
The Headmaster of Yamanouchi, Sensei is the traditional "wise old master" kind of character. His name can be translated to English as both “Teacher” and Master, making the title redundant. He possesses a wide range of abilities, a product of his many years of training and experience. As a martial artist, he is quite powerful, regardless of his advanced years and small stature. He also seems to possess a wide range of spiritual abilities, such as astral projection and the ability to levitate. But despite these skills, Sensei seems to prefer not involving himself directly in conflicts unless he has to.
Sensei was the one who initially arranged for Ron to be part of the transfer program to Japan, which would bring him to the Yamanouchi, in order to protect the Lotus Blade from Monkey Fist, and was the also the one who secretly arranged the adoption for Ron's new baby sister Hana, so she could be prepared for her eventual showdown with Yono the Destroyer.
Like Yori, Sensei has an unwavering confidence in Ron and his abilities and sees him as a true warrior, although this is a mindset Ron doesn't always share.