The netsuke is a toggle. Japanese men used netsuke to suspend various pouches and containers from their sashes by a silk cord. Netsuke had to be small and not too heavy, yet bulky enough to do the job. They needed to be compact with no sharp protruding edges, yet also strong and hardwearing. Above all they had to have the means of attaching the cord.
Netsuke were made in a variety of forms, including this manju shape. It takes its shape and name from a type of rounded sweet dumpling filled with bean paste. Manju netsuke are either solid or made in two halves, as in this case. This netsuke is made from stained ivory imitating a peach stone. On the outside you can see a dog, a monkey and a pheasant. On the inside is a boy. These are all characters from the story of Momotaro, who was found inside a peach.
From the late 1700s onwards, many more makers signed their netsuke. This example is signed Shibayama. The earliest Shibayama work dates from the late 1700s. In the 19th century Shibayama netsuke were typically encrusted with ivory, pearl-shell, tortoiseshell and other materials, as on this example.