I kinda teared up a bit at this scene in the anime and adding this little twist to it now just makes me tear up more, otherwise very good doujin, still kinda sad though. Hopefuly Akather by the same author is translated, seems to be related to this, a sorta sequel or something.
In the series, the two met about a year or more before the anime itself takes place, only Akazawa remembers...and what she means at the end is that she had a miscarriage.