The Okiku Doll is one of Japan’s most famous haunted artifacts, housed at the Mannennji Temple in Iwamizawa. According to temple records, the doll was purchased in 1918 by a young man for his sister, Okiku, who died of illness the following year. Soon after her death, the family noticed the doll’s hair began to grow, and when it was later entrusted to the temple, priests confirmed the hair continued to lengthen despite periodic trimming. Scientific tests have shown the hair is human, but no explanation accounts for its continued growth. Visitors report feeling a strong presence in the display room, and temple monks still maintain the doll’s hair as part of a quiet ritual, believing the spirit of the child remains within it.