Uniform
noun
If you control people, you make them wear the same clothes. That's a uniform.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
高校の制服はセーラー服だった？それともブレザーだった？
Was your high school uniform sailor-style or blazer-style?
あの高校の制服が可愛いことは、みんな認めている。
Everybody acknowledges that that high school's uniforms are cute.
アヤに、制服を着た女の子の絵を、立体派の画風を取り込みながら描いてもらいたいんだよね。
I want Aya to draw girls in school uniforms and integrate cubism style into it.