Birthdate: February 17th, 1981
Zodiac sign: Aquarius
Blood type: O
Chiaki is twenty-one years old and a 3rd-year piano student at Momogaoka Music Academy at the start of the series. He is an accomplished pianist and violinist, but is also known to be a perfectionist and highly critical of himself and others. He comes from a distinguished and well-off family, and is a fairly good cook. He seems to think that most "poor" people (such as Sakura Saku) are like the little match girl.
While he dreams of studying abroad and becoming a famous conductor like his mentor, Sebastiano Viella, he must overcome his fear of flying and the sea to do so (he finally did with help of Nodame's hypnosis).
He is dismayed to discover that the freakish but talented girl, Nodame, lives in the apartment next door to him. However, he develops a sort of empathy with Nodame as he discovers her hidden potential to be a great pianist, and he begins to transcend his perfectionism and begins to enjoy her music and the music of others.
Despite his constant irritation towards Nodame, he eventually develops romantic feelings towards her and he chooses to find a work as a conductor in Paris, where he is going to study.
As Chiaki realizes his life's ambition to become a conductor, he also finds that he needs Nodame's support and that he cannot move on without her. He also appears to have fear of being abandoned and surpassed, the former comes from being abandoned by his father as a young boy. Afraid of being abandoned, he often abandons other people instead, especially Nodame. Also he's constantly afraid of being surpassed by Nodame, trying to go even further from her, which leaves her miserable as she is trying to catch up to him. He also can be considered as insensitive.