Aki doesn't have that many people that would write him letters. Most, if not all of them are dead.
Argo2Unitard
2022-12-15 03:55:42 +0000 UTC
i dont think thats the implication at all
ken_tka
2022-12-15 01:39:11 +0000 UTC
In the manga they're all letters Himeno sent to her sister. The implication being that over time she just wrote more and more about Aki over anything else.
Al
2022-12-14 22:51:17 +0000 UTC
The letters don't have to be from the same person. Most likely they are from various people wishing him well. Himeno's sister said, "THIS is a letter Himeno sent me"... meaning just that one she handed to him.
Also, there is probably a body connected to the eyeball, we just can't see it because it's hidden in that dark part of the cell.