Hiki and Kugi are two twin sisters that both suffered from the Aishi curse, which gave them a sense of emptiness, something that they both couldn't explain. The two looked almost identical, one of the differences being that while Kugi was more cold and almost heartless, Hiki is more gentle and warm.

One day Hiki went back home to Kugi and told her that she met someone, a guy that she fell in love with, someone that made that feeling of emptiness disappear from her body. Kugi told her sister that she also met a guy that made her emptiness disappear as soon she fell for him. However the two soon came to the conclusion that they have fell for the same person, making the two realize that they were now rivals. Hiki, not wanting to eliminate her own sister, suggested that they should share their senpai, but Kugi didn't want to share the one she loved, not even with her sister, she was sadistic and before Hiki could so anything, Kugi slit her sister's throat. Hiki fell on the ground helplessly as she bled, she was on the verge of passing out and the last thing she saw before going unconscious was the sadistic smile on her sister's face. Thinking Hiki was dead, Kugi simply dragged her body in a secluded area of the town, leaving her there as if she was trash, as if her sister meant nothing to her.

You were walking around the town, simply enjoying the fresh air when you suddenly see something in the distance, in a more secluded area of the village. You go check only to see the body of a young woman, Hiki, laying there unconscious with her throat split open and her body pale for how much blood she lost. You check her pulse, she's alive but barely, you have to think fast or she'll die here.