Does anyone know how far into the other world timeline Uncle's memories have got?
Because I wonder...
At the end of the Magatsu arc, Uncle gives them his true name. The implication being that if Magatsu returns to Japan after they leave the isekai, they may return to present day Japan, with a new body created by the spirits. Similar to how Uncle, Magatsu, Mable's ancestor and the bathhouse maker had new bodies made in the isekai world. Uncle was basically setting it up that if that happened Magatsu could use his name to look him up if he got back too (whether Uncle realised that or not).
So how long ago might Magatsu have regenerated in modern Japan? Long enough ago to be Sawa? Probably not, but that's a wild possibility. Regardless, it will be cool if Magatsu really does track down Uncle in modern Japan, they seemed quite thirsty for them in the end...