triangular headpiece
A type of headband sometimes worn by ghosts in Japanese folklore.
Derived from Edo period burial rituals, it was originally intended to protect the newly deceased from evil spirits. It has various regional names—hitai-eboshi (額烏帽子, lit. "forehead headpiece"), tenkan (天冠), houkan ("diadem", only Buddhists use this word), kami-kaburi, kami-kakushi (髪隠し, lit. "hair-hider"), zukin (頭巾, lit. "hood" and also used as a generic term), and so on.
The triangle cloth on the head of Japanese ghosts, known as a tenkan or hitaikakushi, is a piece of traditional funeral attire that serves as part of a white kimono and signals the deceased's status and transition into the spiritual world. While the exact meaning is debated, theories suggest it is a symbol of ascendance to a higher plane, a protective "heaven's crown," or a ward to prevent evil from entering the body, which is why it is found on ghosts like the yūrei
