HIMEGAL OC + how to uniform :')

Hello! I have an oc who I'm trying to make dress hime gyaru. I already understand how to style her outside of school, however,,

She attends a Japanese high school, and therefor wears a uniform! Her uniform is black and red, and not at ALL hime-looking!!!

SO, my question is: How do I make her look hime, even while she's in uniform?? Do any hime gals, gals, or just people knowledgeable in gal fashion have any tips? Please lmk! I don't dress hime or know enough about hime or uniforms, so help is very appreciated! I'll add photos of what she and her uniform look like, as well.

here's a simple, low-effort drawing from yesterday with Ryuji (the girl in the front, whom I'm going to alter to look more hime) in her school uniform. I plan to make her wear more makeup in the future, of course, but this sketch was made while I was still planning how I'd make her dress. (The one in the back is Ami or Amin, a Russian transfer student that pesters Ryu, they become friends later on!!)

here's an image that is similar to what their uniform will look like (I'm not very educated on uniforms, so if anyone has tips please let me know!) The uniform for their school does have the short and long sleeved option similar to this one, as well as a red sweater and sweater vest option and a blazer that I could incorporate if necessary!

You can see with Ami in my earlier sketch that I could make the skirt longer if I wanted, but would it be disrespectful to go shorter with the skirt? I sometimes worry about it, due to Ryu being 15-16 within the storyline.

I frequently see kogals wearing uniforms, of course, but their particular substyle isn't typically specified, so it's hard to find references for himegals in uniform.

Anyway, if anyone has further questions I can always add info to this or in the replies, and please suggest tips to me if you have any!