Yūrei are spirits in Japanese folklore, often depicted as the souls of the deceased who have not found peace. They are typically characterized by their white funeral garments and long, unkempt hair. Yūrei are believed to linger in the physical world due to unresolved issues, such as unfinished business or strong emotions like anger or sorrow. These spirits are commonly associated with Obon, a festival in Japan that honors the spirits of ancestors. During this time, families pay respects to their deceased loved ones, and it is thought that yūrei may return to visit the living. Various rituals and offerings are made to help guide these spirits to the afterlife.