This, for me, is quite probably one of the most touching animes that I have ever seen and one of the more heartfelt pieces of cinema that I have ever experienced. Basically, 5cm Per Second is a short movies split up into 3 episodes, the first one being 30 min, the second one 20 min, and the last one 15 min. Each of these three episodes portrays a pair of people and their relationship during childhood, adolescence, and adulthood. The story that it has is very simple and could be summarized in a few sentences but that is not the point of this series. The real point is the volumes of material that could be written about the emotion, feeling, and beauty that can found in this masterpiece. As you watch this, you will be able to distinctly feel for these characters and you will be able to connect with them as if you actually knew them because of how human and relatable they feel. You will be able to feel exactly the same as they do because in your childhood you will have felt precisely the same at some point and this connection comes through wonderfully. Only adding to this sense of wonder is what might by some of the better pacing in a series to date. Simply the way the characters progress and the way that it seemingly ends as soon as it starts will haunt you for hours or days afterwards. What strongly supports this anime is the excellent animation which stunning and the music, which while not jaw-droppingly amazing, still does not leave anything to be desired.
In short, do yourself a favor, take an hour out of your day to watch this beautiful work of art.