This is a really weird manga, first of all. It doesn't fit any cliches, and the plot is so strange. It's not really romance, but not really not romance. It's happy and light, yet dark and realistic in a way, and it uses many symbols such as his friend passing away as a signal and waking-up call to the main character. It's really interesting, enough to draw you in, and so strange, like you're reading the chapter over to get the emotional feel to it. I can't explain it, but from what I got from this manga was a totally different reading experience from other shounen mangas.
It's not action, it really is more like slice-of-life, and definitely not a typical fighting shounen. It's about two high schoolers, trying to find their definition in life, and the chainsaw man is just a connection to both of them that they both have to surpass to find that. But it's not depressing at all, letting the artwork/dialogue being on the "lighter" side.
The artwork is really good, unique kind of, and fully shows the expression of the characters. The term "a picture is worth 100 words" can be played into this manga. I recommend a read for anyone looking for something beyond the regular shounen.