Hairstyles popular in Japan. Principle: The basic combination of perming agent is two doses. Curly hair is liquid medicine, ionic perm is ointment, and ceramic perm is ointment and water. The first dose will have obvious ammonia smell, which is the necessary chemical component of softening and the culprit of hair injury. Therefore, judging the quality of perm products basically depends on this first dose, and the second dose is basically not too bad.