Japanese straightening is primarily for Caucasian women wanting to straighten their as hair. the chemical ingredient used in the relaxer is primarily thioglycolate based and based on the length of the hair the process might take anywhere between 3-4 hours. 

You hair is first washed and conditioned with a protein rich conditioner. It is recommended you start using a protein conditioner two weeks before the straightening process in order to increase the tensile strength of your hair.  

You hair is then blow dried and the actual chemical cream is applied. This chemical is responsible for straightening the hair. During the application process, your hair is pulled down straight. You might smell the chemicals during this process. Though the chemicals are unpleasant it is not unbearable. They let the chemical air dry and might place a hooded heater on top of your head. Amount of time the chemical need in to be left in the hair will differ depending on hair type. 

After you stylist confirms that chemical has been in the hair for sufficient time you hair is then washed out and straightened using a quality flat iron. Two or more stylists might work on your hair to get it straight.

After this process a neutraliser is applied on your hair and washed out after 30 minutes. As the ions in the hair starts reacting with the oxygen in the air, your hair shouldn’t be washed for at least 24 hours.