Koyomi Mishima - My Dress-Up Darling
Keep in mind that settings may vary slightly between different versions. See below for more details.
When I tested this with different checkpoints and LoRAs, it seemed to work quite well.
Illustrious:
A LoRA weight of 0.8 works great, though you can adjust the strength as you prefer.
Prompts I usually used:
koyomi_mishima, short girl, long hair, brown hair, brown eyes, short bangs, serafuku, white sailor collar, school uniform, white neckerchief, black shirt, long sleeves, black skirt, long skirt,