Here is another picture from the 1957 set of pictures of Japan in Color. Here's what the caption reads for this picture: Boy's Festival: The month of May is the turning point of the season, and is connected with the transplanting of rice seedlings. This picture shows a representative decoration, as well as carp streamers floating in the May sky which are the symbol of the boy's festival. The month of May has always been the season when exhortations were given to youth since ancient times, so it may have been this which helped the officials in deciding to make it a holiday for children.