The Tsurikawa Story
In Japan, the word “tsurikawa” describes objects, usually suspended, that help standing passengers to keep their balance while the vehicle is in motion. In the early days of Japanese public transportation, those handles were made of leather, hence the name “tsurikawa” which literally means “hang” (tsuri吊) and “leather” (kawa革).
The tsurikawas were originally attached inside cars so passengers could slide their wrist inside the ring and safely hang their body outside the window.
They quickly became the symbol of a reckless youth and bosozokus started to attach them outside heavily modified bikes and cars to show rebellion and disrespect to authority.
Reference from https://jdmtsurikawa.com/pages/tsurikawa_story.