Some anthropologists believe the tradition of wearing black at funerals comes from an ancient belief that the spirit of the deceased would try to enter the bodies of the living.
In order to avoid this, everyone present would disguise themselves, believing their dead loved ones wouldn’t take over their bodies if they couldn’t recognize them.
One method of concealment was to paint the body black.
As society moved along and clothes became part of the cultural standard, the family of the deceased would wear black not only at the funeral but for some time afterward to keep the soul at bay.
The color black symbolizes authority and seriousness, and is a symbol of nobility, age, and experience in Japanese culture, as opposed to white, which symbolizes serfdom, youth, and naiveté.
Black is also a popular color in goth and some punk subcultures, and is considered a classic color in the fashion industry.