A Japanese hair straightening treatment involves a solution to break down the curl pattern of the hair along with a blowdryer, flat iron and a neutralizer. The treatment lasts up to six months. It is similar to the Brazilian treatment but does not use formaldehyde as the Brazilian treatment does.
A Japanese hair straightening treatment is intensive and may damage hair, especially if the hair has been colored or had other chemical treatments. The treatment is permanent, and additional treatments may not be applied to the hair afterwards. According to About.com, some salons have discontinued use of the treatment due to its high risk factor.