People aren't all perfect. They're weak, ugly, and they get jealous and try to bring others down. Oddly enough, the better you are, the harder it is to live. That's why I'm going to change this world and the people in it...
Yukino is a beautiful teenage girl with waist-length black hair which is tied with two red ribbons by each shoulder and angular blue eyes. She changed her hairstyle into twin tails when she went out with Hachiman Hikigaya and Komachi Hikigaya (but ended up with just Yukino and Hachiman) to buy a birthday present for Yui Yuigahama. Yukino is mostly seen wearing her school uniform, which consists of a black blazer with a white shirt underneath it, a red ribbon tie, a plaid skirt and black stockings up to her knees. Even though she is seen as flat-chested compared to most of the other female characters, she is still considered to be beautiful.
In the drama CD, Yukino mentions that it snowed at the time of her birth, so her parents named her Yukino which literally means snow in Japanese. Her family is on good terms with Hayato's family. Their families' relationship is not known by many in the school. During her childhood, Haruno would watch over both Hayama and her, when their parents were in a business trip. It was also mentioned that the trio has been to the amusement park where Haruno would mess with them resulting in the fear of rides for Yukino.
She studied with Hayama in an elementary school overseas (the USA in the light novel). It was mentioned that in elementary school her indoor shoes was stolen from her about sixty times, but fifty of those times were done by girls in her class. Her upperclassmen harassed her frequently. All of this due to the fact that she is beautiful and famous, attracting unwanted attention from people.
It was around the time during middle school when Yukino came back to Japan from overseas. She had to transfer into a random school, but all the girls in her class, or rather, all the girls of her school were desperate to drive her out. But none of them tried to prove themselves better than her, to whom Yukino refers as imbeciles. Boys who approached her, generally did so because of their harbored-feelings for her which began from the final year of her middle school.
Yukino is also good at sports but has no confidence in her stamina (refer to episode 3 of the anime). She also can see through people's personality (refer to episode 4 of the anime) and is always honest with her words, though they are often harsh. In addition, she is a good leader as seen when she successfully handled the festival committee in Sagami's stead.
Her athletic skills are showcased in Episode 13. She is also good in academic and extra-curricular activities.Volume 4 mentions that she stands first in all subjects throughout the school. She secured first place in Japanese language, followed by Hayama in second place and Hachiman in third place, an order to which Hachiman referred to as unchanging.
She also won a single match in judo competition as a substitute for Hayato Hayama in Hachiman team using her acrobatics skills. She can also sing and play guitar which is shown in Episode 12. Despite the fact that she doesn't like to stand in front of others.
She is good at cooking and is capable of teaching others cooking, as is shown in episode 1 when she taught Yui Yuigahama how to make cookies, in the OVA when she cooked paella, or when she taught others to make chocolate and cookies in episode 12 of season 2.
Yukino is also good in playing musical instruments and capable of singing infront of a crowd which she normally hates to stand in front of. In Episode 12 (adaptation of Volume 6), Yukino was shown playing a bass guitar and singing. In Drama CD, it was mentioned by Haruno that Yukino loves to play piano.