|Full Name||Kazuki Hihara|
|Age||17 (Primo Passo)|
25 (Blue Sky)
|Hair Color||Light Green|
|Height||178 cm (5'10")|
|Known Relatives||Unarmed Parents|
Haruki Hihara (Older brother)
|Grade||Third Year Class B|
High School Student (Former)
|Created by||Yuki Kure|
|Voiced by||Masukazu Morita (Anime & Manga)|
|Performed by||Kazuki Abe (阿部一樹)|
Kazuki Hihara (火原 和樹 Hihara Kazuki) is a third year trumpeter in the music department of Seiso Academy. He was a fast runner in track club before switching to music and play trumpet. After his graduation, he is now a teacher of Shiseikan High school in an Orchestra Club.
Kazuki is a very enthusiastic, easy going, cheerful, refreshing and caring person who is sometimes childish and he often cheers Kahoko Hino up. He is usually found with a smile on his face that has made him quite "cute" to a lot of girls, as his cheerful personality overwhelmed them.
At one part of the manga, he appeared to have a crush on Hino as he would blush when he was around her.
Kazuki explained to Kahoko that one day he went to the rooftop to have lunch, however when he arrived, there was a female senior playing the trumpet. He was amazed at how she played. Soon after, she was there every time he went to the place to have his lunch. Later, she brought a trumpet she borrowed from the school's music room. This finally allowed him to have a try on playing the trumpet. Nevertheless, at that time, he already joined the school's track team and he was reluctant to leave and join the school band. However, in the end he had his friend's support and quit the track team.
Kazuki has an enormous appetite, as he is constantly eating. He quickly befriends Kahoko. Because of him, Kahoko learned the true meaning of music, that it is enjoyed by everyone. After that Kahoko began to love and enjoy music better. In the middle of the series, he starts to call Kahoko "Kaho-chan", instead of the usual "Hino-chan", because he has a rather obvious crush on her. He is the first one to realize he likes her, and becomes overly conscious of her afterward. When Kahoko commented she wanted to perform well for Len it threw off his own performance due to conflicted feelings. He's a member of the Orchestra Club. He has an elder brother named Haruki. In Kin'iro no Corda 3 he is 25 years old and a teacher at another music school.
- The name Kazuki means "harmony, peace" (和) (kazu) and "tree" (樹) (ki).
- Kazuki's surname Hihara means "fire" (火) (hi) and "field, plain" (原) (hara).
- Like Kahoko and her other potential love interests in Kin'iro no Corda 1&2, his family name has the hi 火 part, corresponding to the planet Mars (火星 Kasei) in Japanese characters.
- In Season 3 Episode 3, Kazuki was shown at the music store of Minami which was closed down and moved to another location.
- In Season 3 in Episode 7, Kazuki appears in a flashback after Shiro Hozumi mentions "Yukihiro Yagisawa-senpai's teacher" this time, who turns out to be Hihara.
- Kazuki never missed a day during grade or middle school.
- Kazuki loves to snack on baked goods.
- Kazuki appeared in a commercial in the manga.
- Kazuki went to track and field during his middle school, though he eventually withdrawn due to his developed passionate love of music.
- Kazuki is a close friend/classmate of Azuma Yunoki.