Since this is Clannad, a work from a gaming company known as Key, you would expect drama and tragedy after seeing Clannad : After Story. Well don't be surprised when you see this 4koma version is a pure romantic comedy/slice of life manga.
If you guys are wondering what is a 4-koma, it's a manga filled with small story bits, which contains 4 pages each, usually filling comedy purposes.Which is why it isn't a complete story like the original, but rather seperate sections of a slice of life manga.
The art is variant. That's because Clannad 4koma is made by multiple artists, each having their own
style of drawing. They also have small comments about their feelings to the visual novel.
Characters are the same. Just that their personalities are put in a more comedic view, unlike the original. Although I did thought Tomoya was more the visual novel version (That means the player) rather than the anime.
I personally like it a lot because it relieves you after watching a sad story (I think you know what I mean). This manga is definetely worth a complete reading, especially Clannad fans.