I am going to save my dislikes of this book for after I finish the series; as there are a few plot points/plot holes I think could be explained when the story is completed.
Therefore, I am going to say that The Nameless City (Book One) is an interesting start to The Nameless City series. It is a fantasy realistically presented as (so far) there are no magics, aliens or other fantastical images or people. While the city itself is a diverse group of people, the main theme seems to center around Asian cultures. The native population of the city I see influences of possible Greek/Roman and ancient Britain feels to the city, but a South American Native look the dress and mannerisms of the people. However, there are influences of Asian cultures here as well. In classic Faith Erin Hicks style, she mixes everything together to make something pretty darn good. It is something new and familiar at the same time.
This diverseness is explained by the fact that The Nameless City itself has been conquered by many people over the centuries, with the original creators of the city unknown to the present day, except for their structures and some books in an unknown language. Everyone has put their own mark on the city. The separations are what keep the people apart and allow the Dao (current rulers of The City) to think a “City person” as “not human.” This is all done at a middle school (ages 10 to 14) reading and understanding level but shows human colonialist history clearly. Yet, it is a fun read. You can see the influences, but you also have a great story set in a graphic novel format about two kids trying to make friends in a world that does not want them to be. A world that prides itself on its separation, but does not realize how their pride, feelings and goals (in the end) are similar. The result is what is different.
You have Kaidu and Rat (one a Dao; the other a native girl with an understandable dislike of the Dao). Kaidu is a somewhat spoiled 13-year-old boy of the Homelands. His grandfather and now mother, were/are the tribal leaders. His father is an important and respected general of the Dao/the city. Rat is an orphan girl with a hunger (literally and figuratively) to exist and stay out of politics. She has a soft interior but a tough outside. Even Kaidu is like that with is wanting to survive the bullies of his school, his classes, his battle training, even the city itself. Yet, he has both a soft inner and outer self. He prefers books to knives. Yet, he has inner strengths even he is not aware of yet. While he is the first to defend an “outsider” he starts to see his privilege as well. We see how the two learn they are not so different; we see them become friends; we see them learn to use their wits when force will not work and we see that when you start seeing the “body” as a person you see the potential everyone has to help save the city everyone loves.