Toukichi is a character of the day who appeared in Ariados, Amigos. In the English dub, he was merely referred to with the title of sensei.
He is the owner of the Pokémon Jujitsu Academy that is in between Goldenrod City and Ecruteak City. When Aya came to perfect and improve her training skills, Toukichi took her under his wing and became her tutor. He and his Ariados helped Aya and her Venonat become better at battling. As well as being the owner of the academy, he partakes in many of the classes that the academy offers. In the class for improving battle techniques, he is the judge for each battle.
After Jessie, James and Meowth stole all the students' Pokémon, Tōkichi, as well as Aya and the gang, chased after them. He used his Ariados's web in order to make a kite. Aya stated to Ash that creating and utilizing the kite is one of her master's greatest techniques. Using ninja stars, he cut the balloon and cut the rope holding the stolen Poké Balls.
(Source: Bulbapedia)
