Mystery utensil

We found this iron object on our farm close to an old house site. It's about a foot long and has Japanese characters of its maker on the underside (a female name supposedly, which is unusual for a blacksmith). The handle has little hearts stenciled into. The thick, flat bottom indicates it's meant to sit on a stove. There's a tiny nudge in the very front. The startling thing is that it has two compartments. So far nobody could explain what it was used for. Even a Japanese archaeologist didn't know. Not big enough for soup or tea. Not practical to spoon something out of a pot. Smelting? A tiny iron for clothing items? Guess it's +/-100 years old.