Have you ever seen Japanese people doing Karate chop in crowded space?
Japanese people often do Karate chop in daily life.
Doing Karate chop is a bit strange without an enemy but it is a common practice of expressing humility.
The Karate chop is called “TEGATANA”.
Japanese do TEGATANA when they want to pass through in front of somebody, especially in case of interfering other people’s view.
So doing TWGATANA means “Excuse me” or “I am passing in front of you”.
Also TEGATANA is used in Sumo wrestling.
When a Sumo wrestler win and receives prize from judge, they do TEGATANA in front of the prize which express acknowledgement.
For your information, this habit is for middle age, especially man and not for the youth like high school girl.