Rear Naked Choke (裸絞, Hadakajime) is a fighting technique.
The Rear Naked Choke is a chokehold in martial arts applied from an opponent's back. The word "naked" in this context was suggests that, unlike other strangulation techniques found in grappling martial arts, this hold does not require the use of a training uniform.
If properly done, it will restricts blood flow to the brain via the carotid arteries, leaving the opponent unconscious. It is very used in Judo, Jujutsu and the mixed martial arts, being the most used strangling technique.
The technique was used by Gaia during his battle with Baki Hanma in the first series. Later, Baki used it against Yuujiro Hanma. In the second series of the manga, Spec used this technique in his fight with Hanayama but failed. Kaiou Dorian also used this technique in his fight with Atsushi Suedou. Later, Izou Motobe also used his technique during his brutal fight against Musashi Miyamoto. Also, Pickle used this technique as well, during his fight against a gigantic crocodile.