This began as part of the education of young ladies, by sewing and giving a small bag to store a koto plectrum as a wish for health and growth with the birth of a princess.
元々は奥女中の嗜み教養のひとつとして、お姫様が生まれると琴爪入れなどに使う袋物を姫様の健やかな成長を願い繕い贈ったのがはじまり。