The sailor fuku (セーラー服, sērā fuku) (lit. ‘sailor outfit’) is a common style of uniform worn by female middle school students, traditionally by high school students, and occasionally, elementary school students. It was introduced as a school uniform in 1920 at Heian Jogakuin (平安女学院)[9] and 1921 by the principal of Fukuoka Jo Gakuin University (福岡女学院),[10] Elizabeth Lee. It was modeled after the uniform used by the British Royal Navy at the time, which Lee had experienced as an exchange student in the United Kingdom.
Is it related to WW2 era navy uniforms, like Donald Duck’s? Or is it some freak convergence?
https://en.wikipedia.org/wiki/School_uniforms_in_Japan
I believe so. They actually are called “sailor” uniforms.