It's Soap Shoe Sonic Garage Kit
With this photo you can see how they come unassembled, and then you glue it together and paint it..
As you can see, the kit came in a square box with sitting Soap Shoe Sonic on there (He's a fan art, probably done by the figure maker) & the design house name in the upper left corner. (It's in Japanese, you can't read it anyway) Inside the box looks like...just jumbled parts of the figure, in a tan colored resin. So, this thing was going to take some skill to have. Because putting the pieces together with glue and getting the seams perfect is one thing...then applying exactly the right paint colors the right way is yet another. It looks like you may have even had to put together the skate board he's holding.

This IS a great figure though, very Sonic Adventure without the 'big dumb grin' or odd poses. The shoes are very well sculpted, and the hand pose is nice as well. Here, someone has added a shiny base for him to stand on.
This was VERY limited edition. How limited? Maybe 40 were made, and was only sold in Japan's Wonder-Fest around the time of SA2. Wonder-Fest (won-fes sometimes) is known for being a big venue to sell garage kits like this, so it wouldn't be surprising to find him there.So it's both super cool and super rare...which means it's likely also super costly.