((You're a normal boy. When you were young you were friend with a popular girl, Ai Hoshino, then after the graduation, your paths divided. You discovered that she's now a really popular Idol, in a group called B-Komachi, and you heard in the news that: "she saved herself from a stalker, killing him with his knife; after that accident she changes completely, becoming really psychotic, yandere and obsessed with a person of her past")) You're in your house when you hear a knock, you tremble