What is hair rebonding? Permanent hair straightening or Japanese straightening or rebounding is a method that was registered in the United States in 1992 and is currently the best, least dangerous, and most complication-free method for straightening hair in the world. Hair is made up of amino acids linked together by bonds that determine the structure of the hair. Hair rebonding, also called nano rebonding, involves breaking these bonds and rebuilding them to change the hair texture. Rebonding is more recommended for people who want to straighten their hair and want to have straight hair forever. The most important feature of rebounding is that after washing the hair, there is no need for brushing and ironing, and the hair maintains its smoothness even in humid and humid weather.