Saju: 

An ancient form of divination, saju analyzes the cosmic energy at the hour, day, month, and year of a person’s birth, and is based on Chinese astrological records and texts. This practice holds the belief that one’s destiny cannot be changed, and is determined solely by the conditions surrounding one’s birth. In addition to offering insights into one’s destiny, saju data is also used by couples to check their gunghap, or marital harmony, which was in the past a precondition of any talk of marriage. If a saju reader determines that a couple is not compatible, one or both of the individuals may be advised to change their first names to improve their matrimonial lot. In the past decade alone, approximately 1.5 million Koreans have taken a new legal name as a result of this.