Rikako (梨香子) was the former general music teacher and band director at Kitauji High School. Her full name is unknown and not mentioned in the light novels.
Rikako is described as gentle and kind, but lacks motivation and passion. She was more concerned about whether or not the students in the band "got along" instead of their musical achievement, and so encouraged the third years to assert power over their juniors.
Prior to the events of Hibike! Euphonium, Rikako took a relaxed approach to teaching the band, but her lax method and casual attitude clashed with the interests of a group of students, comprised of the former third years and the former first years (spearheaded by Nozomi Kasaki). Due to this, the ensemble became divided. There was a following wave of desertion by the unsatisfied first years, leaving behind only a few members, including Natsuki Nakagawa, Yuuko Yoshikawa, and Mizore Yoroizuka.
Rikako was replaced by Noboru Taki at the start of the Hibike! Euphonium manga and anime. She is currently on temporary maternity leave, and is rumored to return by the beginning of Kumiko Oumae's second year of high school, and will thus end any claim to the nationals that Kitauji might have had under Taki's instruction.