Everybody already mentioned this in the other reviews but there's something in this story that keeps you reading it, even if it came across as slow you will find yourself entertained.
The Tragedy genre is all over the story, but in a subtle way, going through the panels feels like swimming in a light but cloudy water, the story is pretty consistent with a good pace, although the lowkey Shakespearesque way to develop the story can be frustrating for some people I consider it bearable considering the concept of a romantic-vampiresque-tragedy theme.
The art is decent as well, what I like the most was the use of visual elements like Chizuna's beauty, as a subtheme of the story, and the depiction of the relationship between Chizuna and Kazuna with textless panels, it feels like they are in a place where no one can reach and nobody can label, as their relationship.
The story's characters' strong points lay in Chizuna and Kazuna, and the way they cope with their condition is well depicted and what stuck with me the most.
The quote "We are lambs with wolves' fangs and wolves' hunger..." left the end with a bittersweet taste, even with the last chapter trying to reconcile the misfortuned nature of the story.
I actually enjoy bittersweet stories and this one is no exception, I liked the pace, wasn't too fast or too slow it was just right, the length is good as well, and the art could be better but considering the year it's ok, I really like Chizuna's character design tho. And regarding the narrative, I'm not much of a fan of the way the story it's told as well so a 7 it's fair for me.