Non-Spoiler review.
This movie is very heavy-handed, and character writing isn't the most nuanced. But nevertheless it brings out its themes quite well, and that's what slice of life main purpose is supposed to be. Instead of the series to be focused on dying, I would say it is actually more on "what does it mean to live?"
We have two protagonist with very different perspectives on life, and the plot is basically them learning from each other what life is from the other side. At least that's what I thought. Unfortunately it is a rather one sided argument as the series conclusion chooses which type of life is the correct answer. While I agree with the message, I thought it would have been more interesting to be able to portray the other side in fairer way.
Nevertheless, the series is heartwarming, great pacing, and a poetic payoff that links back to the title of the series, these things are enough for me to overlook its weaknesses.