Man this series got not love, there isnt even a 1.5 version of this character. Anyways the creator did the MC's sister just because they felt like it. They may do more, but thye're not sure if they will do multiple outfits of them or just 1-2 depending on the character..

Base - suzunek

Casual - pink tank top, midriff, belt, denim shorts, short shorts,

School Uniform - school uniform, sailor dress, necktie,