I found this book at the main branch of our library by doing searches on Japanese words--in this case it was "fuku". which means "clothing". The book came from the stacks, which is why I never saw it when I'd browse the Japanese language books. It's from 1981 and the ISBN is 9784829200803 but it appears to be out of print. The clothing is a bit dated, but there are some basic things, especially in the baby wardrobe, that would be easy to adapt.
The title in Japanese is Akachan O Mukaeru Junbi 3 Sai Made No Fuku Kisekata Tsukurikata which I believe translates to something about Preparing For Your Baby Until 3 Years Old. The book appears to include instructions for diapering, swaddling and includes a pattern for a sling
There are instructions for both sewing and knitting clothing
as well as altering clothing, such as using an adult shirt to make a child's smock
It's really a charming book--I wish it will still in print and I think I will be making good use of our library's online renewal function.