Default appearance:

p3yuko, short hair, black hair, hairclip, pink hairclip, hair ornament, brown eyes, dark skin, dark skinned female, tanned

Winter uniform:

p3yuko-winter, gekkoukan high school uniform, jacket, black jacket, long sleeves, skirt, black skirt, bow, bowtie, red bowtie

Summer uniform:

p3yuko-summer, gekkoukan high school uniform, shirt, white shirt, short sleeves, skirt, black skirt, bow, bowtie, red bowtie

Yuko Nishiwaki, the sport club manager and Strength Social Link from Persona 3.

I wasn't able to add her casual clothes since I couldn't find any footage. I think you need to advance her social link on a weekend in order for her to wear it during a scene? I like Yuko so I'll need to try to do that the next time I play through Reload.