Introduction to Volume 1: Yuuki Katakura, a girl who has inherited a unique genetic factor - commonly known as "Ayakashi" - is called the "White-Haired Head" and feared because of her power and silver hair. One day, while cooperating with the special forces unit "EAT," Yuuki meets a young human man. His name is Taichiro Yamazaki. At first, Yuuki feels uneasy about Taichiro's direct and emotional behavior, but gradually he grows to like his unpretentious personality. On the other hand, there is a...
Quick overview: It's set in Tokyo, where non-human superpowered beings called 'ayakashi' exist. Japan is the only country to have granted them some level of human rights, and they are widely discriminated against and feared. The two protagonists are a man who has joined a paramilitary government/police agency that captures or kills dangerous ayakashi, and an ayakashi woman who is with a different department of the police.
It's a more mature treatment of the "monsters-live-among-us" thing that you encounter in a lot of LNs/anime. Unfortunately I think it doesn't quite manage to keep this together towards the end - it feels like generic tropes creep in a bit - but overall I still enjoyed it and intend to read more. The main strength though is the portrayal of characters - in particular Yuki's loneliness and alienation from society, and the shift in Taichirou's simple worldview.
Difficultywise, I don't think it's terribly hard, but it also gets pretty dense with military/government/political terms and I think if you're not fairly comfortable with those it will be hard to push through - especially the start.