This review will be short and objective.
What is a masterpiece? Nogi Wakaba is the answer.
This is the first arc of the amazing Yuusha de Aru franchise. Actually, it wasn't the first arc to be published, but it is the first chronologically. This novel introduces the world in a great way, so I'd say that this is the best gateway to start in the franchise.
The story starts in 2015, when celestial monsters named Vertex invade Earth and become human predators. The hope of humanity are the heroes, girls blessed with the power to fight against the Vertexes and protect humanity. Seems simple, right? But there
are lots of original concepts that are explored throughout the story that can't be said here to avoid spoilers.
That's the best part in my opinion. The characters are deep. They suffer a lot, they fail to achieve their goals, they fight with each other, they make mistakes... The cast is great and the dark side of people is explored in such an awesome way that makes you really into the feelings of the characters.
As usual, BUNBUN(the same artist of the Sword Art Online light novels) did a very beautiful work here too. The art is consistent and the character design is very memorable.
It was just the best reading experience I've ever had in my whole life. It made me really interested in the concepts and in the ideas covered by the work.
That's it! Nogi Wakaba is a got tier light novel that should be read by everyone. I'd recommend that after reading it, you should go and read or watch Washio Sumi and Yuuki Yuuna too, because this franchise works even better as a whole.