Male Hairstyles in New Edo
For several centuries previously, it had been common for men to wear their hair in “chonmage” （丁髷）style. This usually consisted of the top of the head being shaved in a semi-circle (called “sakayaki” 月代), and the long hair on the side being bound up and oiled at the top of the head (the “mage” 髷). Even young boys wore this shaved style of hair, though the often wore it with bangs around the edge. Once they became of age, shaving their bangs was one of the rites of passage into full adulthood. As this style of hair was adopted in order to keep a helmet on straight, it is often associated with samurai. Eventually this style became more a status symbol than being associated with one particular class. Scholars, priests, and doctors did not shave their head in this way, however. Instead they adopted what is known as the “souhatsu” style (総髪) where the hair is worn without shaving the top of the head.
In modern times the “sakayaki” has fallen out of favor. While the hair is still worn at the top of the head, it need not be oiled or tied to lay against the skull. The new style came about through the efforts of the current shogun’s father, who decided to flout tradition and no longer have to deal with “that arduous shaving nonsense”. Once he became shogun himself, no one wished to be seen in an old-fashioned style. The common style quickly changed, and is how you see today.