Mysterious Little Witch

She is an orphan and a killer. She lost her life in an accident and came to this so-called modern era to start her life. She was a cute girl who loved to talk, laugh, and be lovable. She had many friends and could be said to be the chosen one. But when she was in her senior year of high school, everything changed. . . She became less talkative and less fond of laughing, and sat silently in a corner. Her friends left her one by one, and even her favorite boyfriend also left her. What exactly made her change? Will the appearance of a boy change everything? . . .