Hazuki Katou

Hazuki Katou is a healthy-looking girl with short hair pinned to the side.

Her skin is slightly tanned from past sports, and she often wears a bright, enthusiastic smile.

Her body is athletic and a bit muscular, especially her arms and waist, reflecting her middle school tennis experience.

She often gets small scars on her knees from her active nature.

People around her sometimes say she is like a wild boar or really suited for gym class.

Hazuki prefers to wear sporty, boyish clothes such as hoodies and sneakers in orange and yellow, her favorite colors.

She feels awkward in cute clothes like skirts, believing they don’t suit her.

Personal Data

Birthday: February 13

Height: 155cm

Zodiac: Aquarius

Blood Type: A

Instrument: Tuba

Favorite Color: Yellow, Orange

Hobbies: Tennis

Special Skill: Practiced karate as a child

Likes: Sweets

Dislikes: Vegetables

Hazuki is always cheerful and full of energy.

She is outgoing and never afraid to talk to new people, quickly making friends with Kumiko Oumae and Sapphire Kawashima after they first meet.

She tends to leap into new things without overthinking—joining the brass band as a total beginner because she found it interesting.

Hazuki is optimistic and doesn't dwell on regrets, facing problems head-on.

She's also known for being a little clumsy and sometimes makes goofy mistakes, but laughs them off and keeps going.

Her positive attitude lifts those around her, and she often helps others feel better when they're down.

Hazuki is easily scared of ghosts, even though she tries to act tough.

Hazuki attended Higashi Middle School, where she played tennis.

She chose to join the Kitauji High School brass band right after entering high school, driven by curiosity.

Although she hoped to play the trumpet, she was convinced by Asuka Tanaka to play the tuba because of her strong lungs.

Hazuki received lots of support from experienced upperclassmen and grew as a musician and a reliable member of the band.

She prefers reading shonen (boys') manga for their exciting stories and avoids shojo (girls') manga because they embarrass her.

She lives near Obaku Station, parting from friends by train on her way home.

Hazuki started as a complete beginner on the tuba in high school.

She was chosen for the instrument because of her large lung capacity.

Hazuki named her tuba "Chupacabra," treating it like a friend.

At first, she struggled and practiced mostly basics, like long tones, and did not get picked for the main performance group.

She worked hard without complaining and improved steadily, gradually earning the praise of advanced members like Kumiko and Reina Kousaka.

She didn't play in the spotlight at big events at first but learned the value of supporting others from behind.

By the time she reached her third year, Hazuki had become a skilled and trusted tuba player and helped train new members.

She uses a well-worn school tuba model, YAMAHA YBB-641 II, and always takes care of her instrument.

Kumiko Oumae

Kumiko is Hazuki’s closest friend and classmate, also a member of the low brass group.

They met on the first day of high school and became instant friends.

Hazuki is casual with Kumiko, calling her by her first name and often being physically friendly.

She looks up to Kumiko’s management skills, praising her when she becomes club president.

Sapphire Kawashima

Sapphire, called "Midori" by Hazuki, is another classmate and bandmate.

They joke around together and rely on each other.

Hazuki admires Sapphire’s knowledge and strong will and is inspired by her clear goals.

Reina Kousaka

Hazuki first saw Reina as a perfect and slightly intimidating beauty.

They didn't interact closely at first, but later on, Hazuki became more comfortable and started calling her "Reina."

Hazuki respects Reina’s talent and sharp mind and tries to learn from her corrections.

Shuuichi Tsukamoto

Hazuki at first knew Shuuichi as Kumiko’s childhood friend.

After Shuuichi helped her with her tuba and in a few small incidents, Hazuki developed a crush on him.

Encouraged by Sapphire, she confessed to him at a festival, but was gently rejected, realizing he liked Kumiko.

Though sad, Hazuki decided to support their relationship and returned to being friends with Shuuichi.

Asuka Tanaka

Asuka is Hazuki’s upperclassman and tuba section leader.

She gave Hazuki personal guidance on playing technique and encouraged her to join the tuba section.

Hazuki finds Asuka’s over-the-top personality intimidating at times but respects her musical skills.

Other Key Friends and Bandmates

Hazuki has close and fun friendships with many others: Satsuki Suzuki (who went to the same middle school), Mirei Suzuki (at first hard to approach, but later a trusted junior), and Tsubame Kamaya (became friends as members of the back-up "Team Monaka").

She also helps and mentors new first-year students, especially after becoming responsible for them as a senior.

Joining the Band

Hazuki joined the Kitauji High School brass band as a first-year.

She had never played an instrument before, coming from the tennis club in middle school.

Originally eager for the trumpet, she was guided into playing the tuba by Asuka Tanaka because of her lung power.

Hazuki started practicing with the help of upperclassmen and slowly improved her basic skills.

First Year Struggles and Growth

Hazuki wasn’t chosen for the main contest group in her first year and ended up in the back-up "Team Monaka" with other non-main members.

Although she was disappointed, she didn't give up and instead learned the importance of supporting others.

She also made many close friends during this time.

Finding Her Place and Helping Others

In her second year, Hazuki welcomed and helped train new tuba players Satsuki Suzuki and Mirei Suzuki.

At first, she struggled to connect with Mirei, but they became close after working through misunderstandings.

She again became a support member, stepping in to help and learning more about teamwork.

Hazuki was especially impressed by Yuuko Yoshikawa’s leadership and learned from watching her.

Becoming a Leader

After upperclassmen graduated, Hazuki and Ririka Kenzaki became responsible for training new first-years.

Hazuki’s natural friendliness helped her connect quickly with younger students, and she played a big part in making them feel welcome.

She also served as vice-section leader, assisting Sapphire in running the low brass section.

Facing the Future

Hazuki struggled with choosing a future path, feeling lost while others set goals.

After a college information event with her friends, and advice from her teacher Michie Matsumoto, Hazuki realized she was good at looking after others.

She decided to aim for a junior college’s education department, studying to become a nursery teacher.

Saying this out loud gave her relief and new confidence.

Graduation and Final Performance

After the last contest of her third year, Hazuki retired from the brass band to focus on her college exams.

She got accepted earlier than most classmates and enjoyed her final months of high school.

During the senior class trip in February, which included a band performance in Okinawa, Hazuki was happy to return to rehearsals and even got a tuba solo, cheered on by her friends and juniors.

Hazuki really likes orange and yellow items and often uses them in daily life, from sneakers to pens.

She loves exciting boys' comics, but tends to avoid girls' comics because the romance embarrasses her.

Hazuki is scared of ghosts and gets very nervous during scary situations.

She took the tuba home by train, often getting off at Obaku Station.

Hazuki often gives her instruments and belongings special names, like calling her tuba "Chupacabra."

She is known for her famous, energetic catchphrases and cheerful attitude, reviving the mood when things get gloomy.

Hazuki is described in many illustrations and stories as the mood maker of the low brass group.

Her journey from total beginner to trusted senior in the band is a big part of Sound! Euphonium’s charm.