I know I'm replying to myself but if you read chapter 120 chapter 141 will make a little more sense
Looks like Nasa is the reincarnation of Miko-sama(or Imoko?) from chapter 120.
I think the dish the old lady gave to Tsukasa had immortality potion in it... and she gives again and tells to eat it with nasa (giving him the immortality potion as well) .... Just my theory so now both are immortal but if not its sad like really sad
What chapter?
Holy crap I mean I was prepared about learning she was immortal but dang does that mean Nasa left her alone when he died :(