noun
female high school student
Slang abbreviation from 女子高生 (joshi kōsei). Used in casual conversation and media, often with a trendy or youthful connotation.
See also: 女子高生
あのカフェはJKに人気がある。
That café is popular with high school girls.
JKの制服姿を見かけた。
I saw a high school girl in her uniform.
expression
isn't it obvious?; that's common sense
Internet slang abbreviation from 常識的に考えて (jōshikitekini kangaete). Used sarcastically or dismissively online to imply something should be obvious.
See also: 常考
そんなのJKでしょ。
That's just common sense, isn't it?
JK、わかるよね?
It's obvious, right?