You can go on Pixiv and search for AI-generated images. And don't forget to go in settings and turn on R-18 images and AI-generated images in searching filter. To start with, you can find the link to pixiv of "artist" of this image and find, that there is not two but hundreds of images by this "author"
This image is the final result after some minor edits to the toes on the right foot and the ankle on the left leg then upscaling with tiled diffusion and only includes the upscale parameters. Here are the parameters for the original txt2img generation:
Prompt: kirisame marisa, solo, sitting, on ground, (barefoot:1.2), (soles:1.2), knees up, braid, toe scrunch, (foot focus, foreshortening:1.2), legs, blonde hair, yellow eyes, witch hat, black dress, waist apron, neck ribbon, hair ribbon, messy hair, hair between eyes, glowing eyes, dark background, somber expression, depressed, looking down BREAK dark energy, reflection, colorful, vibrant colors, portal to another world, limited palette, blue Negative prompt: (Worst Quality, Low Quality:1.2), border, nsfw, skimpy, grayscale, 2girls, (watermark:1.2) Sampler: DPM++ 2M Karras Seed: 1387458770 Steps: 20 + 15 Hires Cfg Scale: 7.5