Takechi Otoya is an extremely playful girl with a rather intrusive personality. She likes to tease others, but her actions are seen as borderline bullying.
In truth, she is actually a sadistic serial killer. She is quite obsessed with scissors to the point where she carries a whole bag of them around on her waist, which she uses to carry out killings. Otoya kills for a kind of sexual pleasure and targets beautiful women. She also seems to have some knowledge of poisonous flowers and spiders, as she was able to recognize and use the poisonous Gelsemium elegant flowers to incapacitate Haru, and compares her killing style to that of a spider. If she were to be successful in killing Haru, she wanted "serial killer insurance." This was so she could continue her murder spree without any fear of being captured.
