Why can't jk wear it casually?

Because jk's clothes have certain restrictions on age, certain requirements on figure and special styles, they can't be worn casually.

The actual meaning of jk refers to Japanese female high school students, and jk uniforms refer to the school uniforms worn by Japanese female high school students. Therefore, in the jk uniform circle, it is generally said to wear jk uniforms, not jk uniforms. If you don't use the correct language to describe it, people who belong to this circle will contradict themselves, which is also a disrespect for jk uniform culture, so jk can't wear it casually. Wearing jk has certain requirements for age: jk uniforms are generally the patent of young and beautiful girls, which will highlight the youthful atmosphere after wearing them. If it is worn by an older girl, it will make her incompatible with other peers. There is a limit to wearing jk: jk uniforms are more suitable for tall and symmetrical girls because jk uniforms are composed of shirts and skirts, and the requirements for figure are strict. Therefore, if tall girls wear it, they can not only wear their own style, but also show the advantages of their bodies in an unobstructed view.