Beth Anne

Beth Anne is a comet-like humanoid who appears in the 18th chapter of the manga briefly.

Story
Little is known about the strange girl's story or life. However, she was born in a Nebula (likely the Orion Nebula or Rosette) making her an alien. She was sent down to Earth during the Hailey's comet in 239 B.C. She tries to find her parents, but she realizes that they died just a week after she was sent to earth. While the students were on lunch break, she stabbed herself to death.