Yuko has short light black hair tied into a short ponytail, and wears a red clip on her left side. She has brown eyes. Her skin is a light brown complexion, implying that she may be mixed-race. At school she wears the standard Gekkoukan High School uniform except she wears long white stockings with red lines. When participating in club activities she wears the Gekkoukan P.E. uniform. When spending time with the protagonist on weekends, she wears a black jacket with a pink top, white belt, navy skirt, and high white boots. She also has an athletic and a big butt because of her workout.

She is a hotheaded student and is the manager of the sports club the protagonist joins. Yuko worries about how much she eats, but attributes it to being active.

She is not sure on what she should do with her life. She doesn't even know why she became the sports manager in the first place. It all changes when Yuko helps out a group of fourth grade kids improve their running skills, so that they can use the playground that the sixth graders use. Since the sixth graders are older than them, they feel like they can push the younger kids around, and refused to give them the playground. Yuko agrees to help them improve their running so that they will have the abilities to beat the sixth graders in a race. After a little more encouragement, the fourth graders challenge the sixth graders, and beat them in a footrace. She is usually pranked by a girl that sticks pieces of gum inside her locker. The reason behind it is that in middle school, Yuko started dating a guy in the basketball team but apparently he was dating the other girl first, so now she spreads rumours about Yuko having sex with anyone in the club.

She acts like a mature and expert about sexual activities, but she only had sex once with the guy in the basketball team, though she has a fantasy in which she is fucked by the whole athletic club, including the trainer.