The premise summary really tells you all there is to it. Boy comes back to Japan after living abroad, and the story follows his school life and events after he joins the calligraphy club and shows some talent for the art. It presents the content in a knowledgable and rational way, but the actual content itself is, by and large, very, very boring. There are hints of high school romance angles, but it comes with roughly zero impact on the story as a whole, and just seems optional entirely. The art has a very particular style, which I could best describe as fairly simple, but clean. It's consistentand decently done.
The story pacing is, as implied, slow. Nothing takes place fast; a lot of scenes are little more than practicing calligraphy; fitting, but hardly engaging.
There's probably niche appeal to anyone interested in the topic, and I was intrigued initially, but it turns out I find calligraphy to be extremely disinteresting subject matter as I learn more about it.
I wouldn't bother with this as a casual reader just looking for an entertaining read.