Actually, this song isn't about a yandere, it is about a girl no gets neglected by her parents, Soon forming a collar or smthng. The older she gets, the more she demands attention and ;over and worship from p3ople including her parents so she can feel complete. later on in the song, you may notice the lyrics; ´´Doesnt my confession to you seem like a lie?´´ This may mean that the main character had a crush on somebody and her crush possibly confessed to her, yet she Decides to not go out with him letting the collar take control so she insead can;;s him filthy and rejects himater on apologizing behind his back/without him knowing.