Yama-bushi

I studied Japanese in Tokyo for a year, can speak and read the language, the character is definitely the Kanji for up, but turned upside down. The kanji for down; 'Shita' is (下), which as you noted is the mirror image of the former. I'm not 100% sure however that it had the exact significance I suggest, I'm just going with the most likely obvious meaning. It might also be a guide so that whoever is constructing these swords in a factory knows that the seppa goes 'above' the tsuba parts. Of course, clarification by those with a better understanding would be appreciated, I'm still fairly new to gunto.

Its the character 上 (ue), meaning 'up'. but it's upside-down. Probably means this is the upper seppa.

Hi all, new here. I've been all over the net looking for info on this one at the base of the nakago on the mei side, it's on a sword by Takeyama yoshinao (showato), looks like a pear or apple to me. Anyone seen it before? I'm guessing its a makers kokuin since the sword already has a sho stamp. Cheers