Bio World is back to shirts in summer of 2020 with this new black tee.
Interestingly, this is mens' sizes only (so it will fit anyone), and appears on Amazon (and probably elsewhere). It's called "Digitize Tee", and features classic Sonic hands on hips standing. The background is a grid pattern, but the Sonic graphic is 'digital effects applied' over where he is at the edge of the grid. (So it looks blurry here in the photo where the image effects are going on--to make him look 'digitized') It spells out his name in Japanese letters vertically down the right side. It's an interesting take on classic art.