Half a year ago (!?) I released an inanimate UTAU VB named EUC made from the sounds of plucking a plastic ruler. The design and character concept are based on euclidean geometry. ▶︎ Full demo: https://youtu.be/aZWl92M47Qk ▶︎ Download: http://bowlroll.net/file/338720
His body is fully 2D but he exists in 3D space and is trying to adjust to it. He's very intrigued by humans and wants to learn about their customs and society, for that reason he values being polite and formal when interacting with them (with varying results). He can measure things perfectly just by looking at them but he tends to struggle with properly perceiving the 3D space and so depending on the situation, he may have trouble giving accurate measurements (or any at all). Otherwise he's very much a perfectionist although it's something completely natural to him.
full art, specifically for the V2 version: