After a traumatic event, 13-year-old Ray finds herself in a mysterious place with no memories. Branded as a 'sacrifice,' she faces a cloaked figure, Zack, who initially aims to end her life. However, finding her uninteresting, Zack opts for an alliance to flee the forsaken building. Based on a Japanese horror game, Satsuriku no Tenshi tracks Ray and Zack as they navigate obstacles, unraveling their haunting histories along the way.