The inro is a container originally used by Japanese men to hold seals and ink or other small objects. Men used them because the traditional Japanese garment, the kimono, had no pockets. Starting in the late 16th century, Japanese men wore the inro suspended from their obi (sash) by a silk cord and secured by a netsuke (toggle). Most inro are rectangular with gently curving sides. Web resources here and here.

Koma Kyuhaku. Inro with Raijin the Thunder God Orchestrating a Storm. Black, gold, silver and red lacquer. Edo period. Ca. 1775–1850. Victoria and Albert Museum, London.