She is very quiet and has a destructive tendency. She often destroys things that are considered perfect or tidy. This destructive tendency came from her frustration at having to be completely perfect for her mother's sake, then being mocked and put down by the very person she worked so hard for.
Her hatred of tidiness is reflected by her apartment. Its so messy that you can actually find a bra lying around.
Machi has brown hair that goes right down to the middle of her back and has brown eyes. Machi usually has a blank expression on her face which is also due to her being so quiet, especially in the student council room among the other members. Her height is 5'5 - 5'6 (almost close to Yuki).
Role in the Story
When she and Kakeru were young, their mothers argued over whose child would become the heir to the family fortune (Kakeru was the elder and born illegitimately to their father's former partner, while Machi was born to their father's legal wife) . Machi's mother forced Machi to be perfect in everything. She was often abusive to Machi, deeming her "boring". When Machi argued that she was simply trying to live up to her mother's expectations, her mother continued to treat her coldly. Sometime later Machi's younger brother was born, and everything was settled as he would inherit the money. Machi's parents figured that she was jealous of him, even though she was not.
Sometime after her brother was born, Machi saw him laying on the ground and, thinking that he might be cold, was covering him with a blanket when her mother entered the room and convicted Machi of attempting to kill him. Her parents quickly threw her out of the house, and she consented to living by herself in an apartment.
Kakeru explains to Yuki that that is the reason Machi tends to destroy things that look nice or ruin something that is perfect. Ever since then, Machi has hated all forms of perfection, even walking around in circles dozens of times in clean, unblemished snow because it appeared too perfect.
During Summer Vacation
When Yuki first sees her, she had trashed the student council room.
After Summer Vacation
Yuki, after hearing Machi's and Kakeru shared past, promised to walk in the snow with her the next time it snowed, a promise Machi didn't think he'd keep. Over time, Yuki and Machi grew much closer.
Breaking of the Curse
Yuki called her, asking her to meet him at a certain spot. He was planning on telling her about the curse, but then his curse broke unexpectedly, so he instead told Machi that he loved her. Machi asked him if she could call him by his first name, to which Yuki consented.
In the last parts of the series, Yuki gave Machi the key to the apartment he will be staying in while he attends a university.
Kimi is likely the closest thing that Machi has to a "best friend". Unlike with Kakeru, Machi shows no signs of annoyance towards Kimi's enthusiastic personality and Kimi seems to enjoy Machi's company.
Kimi is also the only person Machi seems to listen to without objection, even going so far as to follow Kimi's advice on how to get Yuki to call her by name (although Yuki stopped her before she could go through with it). It should also be noted that Kimi never brought up the rumors about Machi, suggesting that she either didn't believe them, or she simply didn't care. Machi seems to have some degree of respect for Kimi, possibly due to her honest and open personality.
Since they are half-siblings, the two don't look at all alike. The two don't argue in school, but when he visits her house with Yuki, she is very hostile towards him. Kakeru sometimes uses her as an object of teasing, but usually she deals with it by threatening to strangle him. Despite his teasing nature, Kakeru cares for Machi, doing what he can to help her fit in (albeit in his own eccentric way).
Machi, despite her obvious irritation with his antics, proves to be far more open with Kakeru than anyone else, with the only possible exception being Yuki. She doesn't bother to hide her annoyance with him or hesitate to hit him when he makes her mad. Kakeru, in turn, allows her to do so and never gets mad at her, even when she physically abuses him.
Machi is one of the few who boldly proclaimed her distaste in Yuki, or at least disagrees with the Prince Yuki Fan Club. When Yuki was not chosen as Prince for the school play, Sorta Cinderella, Machi said that Yuki did not meet the requirements to be Prince. Later in the series she becomes attracted to Yuki as he tries to understand her. The two grow close as they learn more about one another. They can relate to each other as they both have endured hardships due to family issues. She even eventually meets Ayame, Yuki's older brother. Yuki understands Machi, as he understands her dislike for perfection, as shown when he breaks a new piece of chalk in one chapter. In another, he promises to make footprints in the snow with her. Yuki eventually confesses to her, when the curse broke although he had been planning to tell her about the curse. They end up dating and she is given the key to Yuki's apartment.
Machi and Komaki seem to have a fairly good relationship. When visiting her and Kakeru, Machi made a point to bring something she knew Komaki would like. Komaki also seems to be fond of Machi, affectionately calling her "Chi-chan". They also seem to relate to one another in that they are both regular victims of Kakeru's teasing.