She's doing a Japanese ritual to curse someone to death. The person performing the ritual must dress in white, wear a tripod on their head holding three lit candles, and visit a shrine during 1:00-3:00 AM. There, the person must nail a straw doll representing the target of the curse to a sacred tree using a five-inch nail. On the 7th day of performing this ritual without being discovered, the target will die. If, however, the caster is discovered they have to kill the person who caught them or the curse will rebound onto them.
