Kenzaburou Ishibashi is Kojirou's old senpai and the kendo coach from Machido High School. He was beaten by Kojirou during a kendo meet long ago in their high school years and seems to hold a grudge against him for that, even if it does not seem apparent. Kenzaburou is also jealous of Kojirou's team, particularly because he has Tamaki Kawazoe, a freshman of Muroe High who beat two of his kendo team members in a practice duel one time. Kenzaburou is a more dedicated teacher than Kojirou, but like his kouhai he trains his kendo team only for his own personal gain.

(Source: Wikipedia)