Summary of Wikipedia article: Japanese kimono didn’t have pockets. They needed something to store their stuff in. So they made containers that they hung from their kimonos’ sashes¹. The part that secured the container to the sash at the top was called a netsuke (“root attached”.)

Here’s a really cute one of a sleeping cat from the 19th century 😻

Update

Here’s another. It’s a crouching tiger 😍