Have you ever read the first chapter or two of a story, or watched the first scene or two of a movie, or the first episode of a TV show, and you just knew it was going to be non-stop awesome? I have. This one's a 10.
It's not perfection, but for everything I can think of as a negative point, I can also argue something positive about.
There's the awkward fanservice in volume 1, which involves child nudity in something of an (innocently) suggestive situation. But that also drops the reader immediately into the middle of the relationship between the main characters, and immediately establishes the Mina is not simply as she appears; their relationship is sometimes awkward, mostly due to Akira's naivety or shortsightedness; that they share an odd trust and love for each other. All of this in the first few chapters, without any of the usual, obvious character introduction you'd usually expect at the start of a story.
The main character appears to be 12, yet lives, dresses, and acts like an adult. I can almost guarantee you'll feel uncomfortable reading parts of this, because of that. But that's good - you're supposed to feel awkward. She's not normal, and it'd be a much more boring story if Mina was an older, dyed-in-the-wool vampire queen. Her youth works strongly for her character; despite all her responsibilities and position, she is young, and does end up having to swallow a lot of her emotions in order to work/live properly, according to her position. The moments when we see Mina blush, or hide something she'd like to say, hit so much harder because of how she's portrayed. Underneath all the strength and willpower and admirable leadership, she is actually scared, and loving, and curious.
It's vampires+werewolves, for crying out loud. Except it's nonstop badass. And the characters have so much depth, you practically feel like you know them personally. It's full of cliche'd battles and insane political drama, but it's what we get of the characters before/after/between all of that, that really makes this shine.
I'm rambling now, but I do feel like this is definitely worth reading, even if-- no, especially if you'll likely find some parts uncomfortable or awkward or annoying to read.