남고 is a 남자 고등학교 or “all boy school”
괴담 is a ghost story or an urban legend
“all boy highschool ghost story” is a more literal translation
분신사바 (bunshinsaba) is an incantion (주술) for calling a spirit that came over to Korea from Japan. This incantation is said to have been famous in Daegu first, but this isn’t certain. It is actually unclear of how and when it spread in Korea. According to a Japanese wikipedia article, kokkurisan (콧쿠리상, a Japanese version of the Oujia board where a mixed animal spirit answers questions about the future) came over to Joseon during the Japanese rule (일제시대) becoming 분신사바. To call the ghost forth you chant 분신사바 분신사바 오잇데 구라사이, “please come to us, bunshinsaba”. (info from here).
-> If you watch that part with Japanese captions, it says “こっくりさん” or “kokkurisan” which is what that article is saying it originated from.
Yedam is listening to “wayo” as his demo (https://youtu.be/k-U9YOXG4Qg)
The word for a “night terror” or “sleep paralysis” in Korean is 가위눌리다 (and 가위 means “scissors” so thats why they talk about “rock beating scissors”)
They are in the 4th class and 사(四) means “four” but is also similar to the chinese for “death” (which is why 4 is seen as an unlucky nunber)
Anyway, these are just the tidbits I was able to notice so I thought I’d point them out! I thought the roster might have clues (like 4 is death but thats not a member and then I realized that duh…it’s alphabetical….lol)