Shiki is based on a novel by the same name published in 1998 by Fuyumi Ono. Although most of the story is almost the same, there are some differences. The main difference is that one of the supporting characters on the novel, becomes a main one in the manga (Natsuno Yuuki).
STORY- Shiki starts as a horror/mystery slow pace story about sudden unexplainable deaths occurring in one small village, Sotoba. The deaths seem to have started since the Kirishiki family moved to the village. Our protagonists are Muroi Seishin the monk, Ozaki Toshio the doctor and Natsuno Yuuki a student and the little mysterious Kanemasa girl named Sunako Kirishiki. While the supernatural events occur, later the drama starts and that´s when you get addicted. The bonds, the friendship, betrayal and pain. You cannot stop reflecting about the nature of humans and vampires, and who of them is right or wrong.
ART- Considered as ugly by many because of the weird hairstyles and colors, i personally find it unique. The hairstyles sure are weird and so are the outifts, but once you´ll get used to it, you cannot imagine them with normal hair or clothes. You´ll even start to adore them. They´re fashionable. The art must be unique because its a unique manga.
CHARACTER- All characters in Shiki universe have name even the ones who almost do not appear. Many of the supporting charas had full chapters dedicated to them. Some people may find it boring because that way the main characters have much less "screen-time", and it certainly leads to a bit of anxiety waiting to see the main characters, because their chapters end always in a cliffhanger and you want to see what´s next, not the story of a random supporting character. But that keeps you even more excited.
The main characters are extremely well constructed and with a very detailed personality. You´ll love them or you´ll hate them, there´s no "middle" here.
ENJOYMENT- A great one. Once you´ll get through the slow plot of the first chapters, later the story takes a twist and everything starts to happen fast and in a twist. You will get hooked, you´ll be cheering for your favourite characters and cursing the ones you hate, because this manga gives you a mountain of emotions.
OVERALL- Outstanding. And here you´ll get the chance to see the "continuation" of the characters you saw in the anime or novel version.