spirit behind one's back; guiding spirit; ghost
Refers to a spirit that is believed to follow or stand behind a person, often acting as a guardian or a lingering presence. Can be protective or haunting depending on context.
She always feels like she is protected by a guiding spirit behind her.
A spirit behind someone appeared in the spirit photograph.
幽霊 is a general term for a ghost or apparition, often associated with haunting a place, whereas 背後霊 is specifically a spirit that follows or stands behind an individual.
Compound of 背後 (はいご, 'behind one's back') and 霊 (れい, 'spirit'). The term is used in spiritual and occult contexts to describe a spirit that is believed to be positioned behind a person.