Having already read Hitsuji no Uta, the style of this volume is very familiar to me. This story lacks any of the drama of HnU, but has a more uplifting ending.
As others have commented, don't expect any suspense or surprises. Instead be in the state of mind for a quiet, contemplative experience. The characters are developed only in the sense that they each have a brief story to tell. The stories are interesting, and may give rise to some self reflection if you find you can relate to them.
The art is very nice, and the black and white chapter at the end works just as well as the full color chapters from the beginning of the book. IMHO, Tomei Kei's drawing style works very well in black and white. The female characters are rendered beautifully, and almost every panel with Ian is a work of art in its own right.
It seems that without any kind of plot there is no reason to explore the characters and their relationships very deeply. The stories work just fine, but one could imagine ways to expand the continuity for a volume or two longer without much effort.
Overall it's a very pleasant read that doesn't quite reach it's full potential. Still it's a very worthy contribution, and anyone who's enjoyed Toumei Kei's other works should consider this strongly recommended.
The supernatural and fantasy elements aren't strong enough to support a recommendation for those genres. Fans of drama and slice of life should definitely consider reading this.