2화: 고등학생들이 동굴을 탐험하던 중 토모코가 반 친구들과 헤어진다
2018년 7월 14일 방영
A group of high school students is visiting a certain cave on a field trip. A small group of them enters a corridor leading away from the main cave... but one of them, Tomoko, is ultimately left alone. After a few moments, she hears the screams of her classmates from deep inside the cave... (Source: Crunchyroll)