I've just put this yatate inro on my website. It's a small bronze ink case that would be paired with a thin brush case and hung from a man's obi with a netsuke. The top compartment has a little wad of cotton and would be filled with ink to make a portable writing set. It dates from the 19th century and is only 3 or 4 cm long but is very solid and weighty. I love this - but I can't keep everything!