https://civitai.com/models/596388/mii-konori-a-certain-scientific-railgun-2-outfits

prompt

School uniform - konori mii, black hair, short hair, black eyes, glasses, konorischool, school uniform, short sleeves, yellow neckerchief, white shirt, collared shirt, armband, blue sweater vest, untucked sweater, grey skirt, pleated skirt, white socks, loafers

Bikini - konori mii, black hair, short hair, black eyes, glasses, konoribikini, white bikini, polka dot bikini, frilled bikini

Note - There is an issue with the 'white socks' prompt being implemented differently than the original anime.

Also, it is possible to implement winter uniforms to a certain extent.

School uniform (winter) - konorischool, school uniform, long sleeves, yellow necktie, blazer, grey jacket, white shirt, collared shirt, armband, grey skirt, pleated skirt, white socks, loafers

https://civitai.com/user/Player1ready