Create an anime-style illustration of a cheerful girl with medium

Create an anime-style illustration of a cheerful girl with medium-length dark hair. She is wearing an oversized black sweatshirt with a large, abstract smiley face graphic on it. The girl is posing with one hand making a peace sign near her face and is winking, smiling brightly. The background should be a graffiti-covered wall with a mix of colorful splashes. The artist's signature 'Sushi JK.' should be included in the corner of the image.