Board Thread:Manga/@comment-5774380-20160908231942/@comment-30142915-20161004162018

Since everyone thinks the persons in the photo are the main cast's younger selves, I'd like to point out that it also mean the society outside the walls have already progressed far (probably 30-40 years) from the time when the photo was taken. What we think is a late-19th century society based on the photo might have already become a 1930s/1940s-ish society by the manga's present day.