What does 「髪を切る」mean?


I know that it literally means "to cut hair" but it was used as following:

> おはよう！ 髪を切る

Is this an idiom, and if so, when do you use it?




I think you mention the sentence from Gintama "第69話「ゴミの分別回収にご協力下さい」". Kagura
said "おはようございます。髪切った？"  
[Someone tweeted the
part.](https://twitter.com/kondosang/status/903994886692544512)

This is just a Joke. NOT idiom.

I think it is too difficult to understand this joke for those who haven't
lived in Japan for long time.

To understand this Joke, you need to know the followings:

  1. The very famous TV show "世にも奇妙な物語", horror TV show.
  2. The famous music in the TV show. (the similar music is played in the Gintama's episode)
  3. The very famous Emsee of the TV show, "Tamori"
  4. Tamori often asked everyone "髪切った？" on other TV shows.
  5. So, some comedian like コージー富田 imitate that, "髪切った？"

Then, it looks a horror in this Gintama's episode, "第69話「ゴミの分別回収にご協力下さい」".

Kagura imitatied/copied "Tamori" after she said "おはようございます。" to wake Ginchan
up.

Anyway, this is just Joke/parody.

I don't know who said "おはよう。髪切る。" and what context it is, but I think he/she
imitated this joke/parody.

