This manga is very good. I think it might be underrated.
I wouldn't label it as a romance manga. If there is any kind of reference to romance it is only as a trigger to show some other kind of conflict. The manga does deal with love, but not romantic love... rather fraternal love, or family.
Story: 10
It includes 6 unrelated stories (one of them is two chapters long), that vary in length and in depth. Some of them have a more elaborate plot; others are more like a glance to the characters feelings. Some of them have a fantastic components, others don´t. Most of them deal with the relationship between siblings (except for the second and the fifth -chapter 6- stories, which don´t).
1) Shiki no Zenjitsu: it is about a man who is getting married. Cannot tell much more without spoiling, as it doesn´t have much of a plot... it is all about emotions.
2) Azusa Nigou de Saikai: tells the story of a girl that can only meet her father once a year.
3) Monochrome no Kyoudai (Monochrome Brothers): it goes about two brothers that were in love with the same woman, and how they dealt with it.
4-5) Yume Miru Kakashi: a man returns to his childhood town for her sister´s marriage.
6) Juugatsu no Hakoniwa: a writer is visited in his dreams by a crow that announces death.
7) Sorekara: a cat analyzes the nature, mood and behavior of his master, and his reaction when he receives a call from his brother in law.
I especially recommend the second, third and fourth stories.
Characters: 8
As they are all short stories, there isn´t much of a character development, but the characters are all very realistic and "imperfect", which is what I like most. I guess, after reading the whole book, the feelings I get from the characters are lonelyness and sorrow. But that doesn´t mean they are all sad characters... just like in real life, sadness and happiness coexist.
Art: 10
It is very good. It is very realistic, and there is some sharpness to it that goes so well with the stories.
In short, I highly recommend reading this book.