Clannad was something that made me change my views on normal slice of life animes in general. Although I do admit that watching the first few episodes did not change my mind (although rewatching them again after it was absolutely fantastic!). I do agree that it pales in comparison with After Story, but it is nonetheless great and tremendously better than your average slice of life anime or any normal anime even.
Story - 9/10:
The story was great overall since it does not only brought about the depth of the characters but on how effective the way the stories were told. You can have any normal story of how this girl becomes an orphan, or how this guy could not be the person that he wanted to be because he could not play the sport he wanted to because of a terrifying event - and all of this would still be obscure in its meaning if it wasn't told properly. Clannad does not have any problem with that. It brings about events and tells them so effectively that the viewer would easily get immersed with the plot easily.
Characters - 10/10:
Here is where Clannad shines best. All characters are intriguing not because they are mysterious, because they're not (well not that much). They are however so complex in such a way that they are thoroughly human. Don't get me wrong we have Sonohara as this normal comic relief but even he has some depth in him and he shows it subtly. Though tsunderes supposedly are complex but have now become stereotypical, Kyou is different to me because precisely of Ryou, her sister. The dynamics between the two shows how these characters are quite different from standard anime stereotypes (though I am a bit disappointed that they do not have their arcs). Nagisa however, at first seems stereotypical but she would have her character development late in the season, where it is absolutely terrific (in my opinion of course). Then there is Tomoya, the delinquent, in which I think though is the most developed character in the course of season one. Other characters such as Fuko, Tomoyo, Sanae, Akio - all of them are also well written.
Sound - 7/10:
I particularly do not like the sound much, since it is not very distinct with other animes but it is good nonetheless. It does not affect the anime, at least and provides a good way to fill the silence. The one thing I like however is the Big Dango Family song, which is really memorable and quite catchy.
Art 10/10:
Of course, with Kyoto Animation's works you could only expect the best. Clannad here is no exception. The places, characters and facial expressions are all so well drawn and so beautiful.
Enjoyment 10/10:
I did enjoy Clannad greatly. When I finished it, I know I will have to watch it again. I know that After Story is way better, which a lot of people do say. I even agree. But Clannad is great nonetheless. It made me smile, made me feel sad - within a single episode or within a single scene.
Overall - 9/10:
Clannad truly is a great anime. The reason why I gave it a 9, is how I think it did not utilize its full potential yet (which is of course, apparent in After Story). It already knows how to explore its characters but it lacks the great ending (good but not great, and of course in my humble opinion). Still, a great anime.
