I mean, it says that Menhera Gyaru Will Confess in 10 Days begins which is word for word this one https://mangadex.org/title/1fef7913-988d-4bf0-9c99-51b34eaecac9/menhera-gyaru-will-confess-in-10-days so i think it might be safe to say it's saying that it continues to this one?
@Aldis the original is dead, it was mentioned that she died from a fever and after that MC entered her body so her soul should've gone to wherever dead souls go to in that world.
So if their expedition hasn't even failed and there's already an outsider knowing that it's a bad idea to join. I wonder what happened to the girl that joined.
@Niconicoknee you forgot the part where the girls fall in love with him. There's also the chance that he ranks higher than them cause he was adopted by a bigshot (can't remember the family's rank)