These dolls were used by the people in order to put all their bad spirits on them. There is a certain doll that was made out of paper that they would use for this same purpose and send it away on the water that all their "badness" might float away.

Even in a culture that emphasizes respect for the fellow man, the Japanese and man throughout the ages still have that issue with sin. It is only by the blood of the lamb that we are saved and can sin be removed from us entirely.