"A draw? Are you kidding me? We’re not losing this, not to them."

Yumiko Miura is a popular girl from Class 2-F who is the main female figure in Hayato Hayama's clique and a 'friend' of Yui Yuigahama.

Yumiko is an attractive girl with slightly wavy waist-length blonde hair that has bangs hanging over on the right side of her face (her bangs hang on the left side of her face in Season 2 & Season 3) with curly chest-length tips at the bottom and olive-green eyes.

Yumiko is mainly seen in her school uniform: a black blazer with a white shirt, a red ribbon tie, and a plaid skirt. With her uniform she wears black thigh high stockings that are embellished with white stripes

Yumiko's personality is pompous. Due to her popularity, she is held in highest hierarchy. Hence, she has no trouble making friends and also has little to no understanding towards people who have social troubles. Yumiko doesn't show interest, or mind anyone other than higher hierarchy of the class, which is noted by Hachiman Hikigaya by her attitude towards him. She holds herself in a very high esteem, and is not afraid to use her authority.

Most of males in her class sees her as a scary being. Hachiman once commented that her glare resembles an anaconda. It may be seen sometimes as if she forces her ideas onto the people whom she calls her friends. She doesn't like the idea of being opposed, turned down, or getting an answer not what she expects; this is shown during tennis court showdown, where Yumiko wanted to play tennis and doesn't heed to the words of Saika Totsuka, who got prior permission to use the court during lunch time.

She feels that cooking and cleaning is old fashioned. One time, she avoided cooking in summer camp in order to protect her nails from damage. Despite this fact, she tried her best to make chocolates for Hayato Hayama.

It was mentioned by Yukino Yukinoshita that Yumiko wears expensive makeup. Yui Yuigahama also pointed out that her cosmetics and dresses are of high cost. She uses cuteness as crucial criteria in choosing friends with whom she hangs out with.