Sakura School DX: Repeating Harmony & Dissonance

OJ is a high school student who has problems at school because of bullying and endless torment, and at home because of his sister's physical abuse towards him simply to relieve his stress due to his father's expectations on him. While browsing the web, a website showing a terrifying person suddenly appeared on the screen. This person seems to feel sorry for him and how misfortunate he was, and announces that he will give OJ an murder weapon, and it was up to him If he wanted to use it or not.