It's a little hard to characterise the stories. The narrator uses a speaking voice, mostly close to written Japanese, but with occasional features of spoken Japanese, particularly the particle ね, a question particle, a bit like a parenthetic "you see?" "hmm?", which looks for the reader's or listener's agreement. All the stories have an element of fantasy, so that animals or inanimate objects may talk or in other ways show human characteristics. This is a bit like A.A. Milne's "Winnie the Pooh" stories; but the fantasy is only part of the Momo stories. The focus is on family life and the development from baby to child. The animism is perhaps a view of how small children see the world around them (or are encouraged to see it by their parents). In this the book is a bit like Richard Jefferies' Wood Magic, but without the single minded concentration on the viewpoint of a single solitary child that that has.
The stories are mostly light, cheerful and short (five or six pages long); but some of the longer ones are ready to look at darker sides of life too. Here, for instance is part of a dream that the mother has a little before Akane is born.
Mama was trudging across a plain. Lead-grey clouds hung low over it. The plain was withered. Withered like that, you would expect it to have the colour of dead grass; but, perhaps because of the low hanging lead-grey cloud, the whole plain too was sunk in the same lead-grey.
Sometimes Mama would stop walking and look around. An icy wind blew past. But the damp layers of lead-grey cloud did not move, they just hung there darkly.
Mama sighed and started walking again with heavy steps. It's so dark, and lonely too, as if everything had died out, no sound anywhere .....
Did the baby die, perhaps? When I fell on the stairs, did it die perhaps? That's it, it died. I mean, it's so dark here. Like litter blown this way and that in the wind, mama stood swaying. That's it, the baby died .....
At that moment from a crack in the clouds one ray of light fell on the plain. And there where the light fell something was shining brightly.
"I wonder what that is ....."
The Japan Foundation website tells me that both books have an English translation: Margi Haas, Little Momo Chan (Kodansha International, 1985), Christopher Holmes, Momo Chan and Poo (Kodansha International 1986).
[Update 19.5.14: When I first put this up, I had (I can't imagine how) strangely misread, and so mistranslated a word in the quoted text above. Sorry about that.]