I think this is one of the only manga I can truly say that I was completely invested in its story and characters. While I do think that it is relatively simple in nature, there's something that really compels me to keep reading. It really riles up your emotions, which I think is very important for the viewers to be keep being interested in a story.
There's an unusual amount of character development. While it varies from character to character, I think that the best example for this would be Himawari. She's really only been there for a couple chapters at best but it's been an absolute fucking rollercoaster after she appeared. Her first appearance akin to being a prostitute and the later chapters ending up with someone like that (no spoilers).
The obvious, biggest problem about this is the art... It's not really debatable, it's just meh. Panels that are basically empty, and panels that repeat for no reason at all. It's not really that much of a concern, but that can definitely be a deal-breaker for some people.
I would recommend it. The only problems I can really think of other than the art is that it can get a little boring at times.