After Piitan attempts to commit suicide with his friends in Chapter 2, he suddenly vomits up a bizarre circular gemstone. Barrachi asks to keep the stone, intending to inspect it. After having the stone valued, it is discovered that the stone is a new, undiscovered mineral. While examining the stone, Barrachi is shocked when the stone produces a human-like aura for a brief second. Piitan remains ill, and Marusou takes him to hospital. A doctor using an endoscope examines Piitan's stomach but finds no abnormalities until he looks at the pylorus, seeing something that makes him flee the room.
Later that day, Marusou theorizes that somehow, the gemstone came from the afterlife, where huge amounts of them can be found.