Pretty awesome installment. I'm genuinely saddened to hear there may not be another. I was just getting into it. :(
I do have to say, some of the animation is a bit laggy and choppy -- or just not natural, such as the straightening fingers at some points. This looks like MMD though so I can understand.
Voice actors are also mixed a little strange. Distorts at some points.
However, as a whole, it transcends its parts, and the story overtakes any animation issues. Very nice work, all involved. There isn't a single point where it feels disingenuous, and that's an achievement.