Wikipedia
Yūrei
are figures in Japanese folklore, analogous to Western legends of ghosts. The name consists of two kanji, 幽 (yū), meaning "faint" or "dim" and 霊 (rei), meaning "soul" or "spirit." Alternative names include 亡霊 (Bōrei), meaning ruined or departed spirit, 死霊 (Shiryō) meaning dead spirit, or the more encompassing 妖怪 ( Yōkai) or お化け ( Obake).
Like their Chinese and Western counterparts, they are thought to be spirits kept from a peaceful afterlife.