1. Tears are enough. A lot of people commented that they were crying. The tags and keywords are healing, tearjerking.
2. High ratings. Especially the second season.
3. Grow with the protagonist. When I watch it, I feel that the protagonist is someone you know well. He is happy and you are happy too. He is sad and so are you. This feeling is empathy, it is difficult to do.
4. Moe. There are many cute girls in the film. The character creation is very successful, especially the characters, which are different, very individual, and easy to distinguish, not one thousand people.
View more about Clannad: After Story reviews