>>536440414
It was the JAM to CHAN timeline, literally
The only difference is sensei arrived at Abydos a year or two earlier, so he helped things not go fully off the rails. Yume didn't go off on her own that day, Hoshino never went full edgefag, all they needed was an adult to be there. Because they didn't go off the deep end, Hoshino still wants to go on stupid treasure hunts, and Yume is still normal and alive.