Hazuki Katou (加藤 葉月 Katō Hadzuki) is one of the main characters of the Sound! Euphonium series. She is Kumiko's classmate and looks a bit suntanned because she belonged to the tennis team when she was a junior high school student. Hazuki plays the tuba in Kitauji Concert Band Club.
Hazuki has the appearance of a young girl, with short, straight brown hair, that curls at the bottom, and gold-hazel colored eyes. She has a red-pinkish hair clip which she accessories her hair with. She wears the normal Kitauji High School female student uniform for first-year students.
Hazuki is a bright and perky mood-maker and also very energetic and cheerful. She is almost always seen with a smile on her face, and she can quickly become familiar with people, which is seen in Episode 1 when she refers to Kumiko as "Kumiko-chan", even though she just met her. She is a friendly girl who talks innocently and she is the type of person who prefers standing out to supporting others.
Hazuki was on the tennis team in junior high school and is a beginner in music. She admired the trumpet and joined the concert band, but ends up playing the tuba.
Hazuki makes her first appearance in Welcome, High School, where she becomes one of Kumiko's first friends upon entering Kitauji High School. Just after meeting Kumiko, she starts calling her by her first name and telling her to do the same thing with her too, which quite shocks Kumiko.
- According to the official Sound! Euphonium novel website,
- Her favorite colors are yellow and orange.
- Her hobby is playing tennis.
- Her special skill is having done karate when she was small.
- Hazuki (葉月) is the old Japanese word for the month of August. It is also a Japanese surname and given name.
- Riko Nagase often encourages Hazuki to do her best.
- Kumiko, Hazuki, and Midori are all in Year 1, Class 3 in the novel series.
- Hazuki is from Higashichu Lower School as the novel series states.
- In the novels, Hazuki is portrayed differently in several aspects:
- She dyed her hair.
- She has/had a trumpet charm on her bookbag.
- She is said to be athletic because she was tan.
- She originally wanted to play the trumpet before picking up the tuba.
- Hazuki's homeroom teacher is Michie Matsumoto.
- Hazuki's tuba is based on the Yamaha YBB-641 model.