This doll belonged to a 3 year girl named kiyoko and was given to her by her older brother, Eikichi Suzuki, who bought it in Hokkaido. The doll
    was named 'okiku' and was very much loved by kiyoko until her sudden death caused by a common cold in 1919 when she would have been around 
    4 years old. The doll was put aside for around two whole decades and in 1938 was given to the Mannenji temple by kiyoko's father and was 
    desplayed on an alter. It was only noticed in 1955 by a priest who was cleaning the temple that the doll's hair seemed longer than before 
    (The doll originally had short cropped hair) and that the hair seemed to continuously grow. This lead to the conclusion that the doll was 
    possessed by the spirit of kiyoko and after the discovery a memorial service was held. The doll still remains in the Mannenji temple to this
    day, with it's hair grown past it's arms. Okiku is given a haircut every now and then.
    
    English sources for the story had limited details so I checked japanese sources with better results (with auto translate so the details may 
    not line up perfectly)
    
Okiku at the Mannenji temple