A supremely gifted artist, Hagu's immense talents are esteemed by all who witness her works, catching the eye of numerous professional artists who insistently urge her to submit her work to exhibitions to heighten her publicity (which she seems to find daunting). She is 18 years of age at the beginning of the series and her appearance is that of a child, and she conveniently behaves as one. Raised in a largely sheltered and obscure home by her irritable grandmother, her sociability is below average. It is whilst living in that home that Hagu develops her skill in drawing and painting, her only past-time, though she finds nothing to sketch save for the never-changing view she has from her porch, varying only in seasons. Hagu is from Azumino city, Nagano-ken.
She is introduced to Takemoto, Morita and Mayama by Shūji, her father's cousin and also a professor at the college. Upon seeing her, Morita and Takemoto fall in love with her, though both express it in different ways. Hagu knows not of their feelings towards her, but sees them as friends. However, Morita expresses his love for her in very odd ways, and Hagu is often seen trying to escape from whatever shenanigan Morita has planned for her. Though later Hagu develops feelings towards Morita, although she does not at first realize this, as Shūji points out.
Hagu is very shy, and because she is so nervous when interacting with people, the other art students think that she is strange. Hagu doesn't seem to be too close with family members either, with the exception of Shūji, whom she fondly calls "Shū-chan". However, as the series progresses, Hagu is able to become closer friends with Takemoto, Mayama, Morita and Yamada. When Shūji leaves to go do a research project in Mongolia, Hagu forms a deeper bond with each of them, essentially seeing them as a sort of family. Hagu lives with Yamada (whom she calls "Ayu") when Shūji is away and they become very close friends.
During parties, she is seen to be crying because of her envy of Yamada's beautiful legs and beautiful breasts. Mayama tries very hard to comfort her but failing rather miserably saying that "You'll have one of those when you're older....probably". While Hagu is crying, Morita is also crying because of her infectious tears.
Later in the series, Hagu started to avoid Takemoto after he confessed his feelings for her, leaving doubts if his love for her is reciprocated or not. In the latest manga chapters she admits that she likes Morita, but would rather be with Shūji because she knows that he can take care of her (especially after a life-altering accident that may permanently impair her abilities as an artist).
