Children (Ichimatsu)
Kimekomi, Gosho
Some traditional Japanese types and some more modern versions.
Boys' Day
Girls' Day
Storytellers
Others
These dolls are play dolls. They have a neck joint and fitted, bent arms and legs, and often have "cryers" in their tummies; their clothes come off. This style of doll originated in the West around 1920 and was immediately adapted for export in Japan, though it was not until the 1930s that dollmakers began thinking of making ones that look Japanese for the home market. Note that the boys are always dressed in cool colors, the girls in orange or red.  

Dolls like these, even when made for export, convey the Japanese sense of spirituality in children. In his 1955 book, Tokebei Yamada refers to them as "Yamato ningyo," or "Truly Japanese dolls."

These babies are haihai, tiny crawling babies not even an inch high. They are a classic development of the gosho doll, but this pose is also adapted in some larger baby dolls with 5-piece bodies, like the ones above.
To the right are three cloth dolls made in the style of the ancient hoko protective doll. All are fairly new, and the small ones are obviously also haihai dolls, little crawlers. The bodies are made by sewing a rectangle of cloth to make the four limbs, with a seam up the front for the tummy, and then adding the head and bib. 

I don't know much about this little guy--except that he takes a good picture. His hair is painted and his costume evokes a boy's festival, with auspicious armor and animals. He may be an older example of the bent-leg babies in the first picture, or just an unusual example.
This guy is a Japanese doll made for sale in Japan. Like the haihai dolls, he is not wearing much, just a bib and jacket. He is meant to be dressed by the new owner. Although he does not seem to be very old (maybe from the 1970s?) he wears a fancy hairstyle, as if he were a samurai child two hundred years ago.
Two  izumeko dolls, or babies in baskets. These represent babies tucked up by their parents to be transported safely to a farm worksite. Notice the toys tied to the blanket. Both little boys have hairstyles that evoke the shaven patterns of the 18th and 19th century.
I include this pair because someone may be looking for them! Dolls like these, ranging from about 4" to about 10", with bisque heads and jointed composition bodies, were made in the 1920s and 1930s in Japan. Usually you find them dressed as Chinese children, as here, but sometimes there is one in a Japanese kimono or dressed as a Western baby. They were still being sold in the 1950s.