It wasn't necessarily bad but sadly it didn't have something that special about it so as to call it good. Definitely not memorable, just a quick cute read.

Story 6
The plot is lighthearted, based mainly on comedy. One of the key points of the humor seems a bit more common to Japanese people than westerners and that is blood type. In Japan, there is a superstition linking blood type with personality just like some other people might associate a zodiac sign with personality. The main theme, kind of predictable, is "let's all just get along, human or non-human". There are many others series doing this theme a lot of justice ( see Jitsu wa Watashi wa which also does comedy so damn good), but this one just lacked any of the conflicts associated with it.
Spoiler **** Everyone in the class seems to just not mind that their classmate is a vampire.

Art 8
The art was great, I liked how all characters looked. Their images fit their personalities (almost absent)

Character 4
Everyone except the two main characters is just bland. We don't know anything about them mostly, just few key things and it's just left at that. Even the main characters fail to be that relatable and interesting.

Enjoyment 5
It was funny in some ways. Though it's good it was short cause probably I wouldn't have had the patience had this been a longer story. At the same time, this is a shame. Cause maybe the story would've gotten much better if they got to develop the relationship between Mana and Okamoto-kun. So much potential is lost.

All in all, this is not a must read. You could give this a try if you want a short angst-free vampire story. (I love angst tho).