I suspect that the training corpus may have been a table of Unicode glyphs rather than text from the wild.
Unless you're using something like Emacs which lets you point at a character and ask the editor to tell you everything it knows about what's there, this kind of identification becomes a daunting task to contemplate. Shapecatcher does an excellent job of it; as long as you can draw something roughly approximating the glyph you have in mind, it'll very effectively winnow down the search space to a very manageable list of possible matches.
If you already have the character in some text file, it would be much easier and reliable to copy and paste it into some unicode table lookup tool (e.g. https://unicode-table.com/en/).
I did see the link to your thesis on captcha, but a specific higher level blog post on how this works would likely be popular.
Edit: One piece of feedback...it's hard to draw dots. You have to drag the cursor with the button down, or drag your finger in mobile to get a dot. So dots end up more like little lines. Also, an "Undo" to remove the last "cursor down / draw" event would be nice. Starting over for every line is the only current option.
e.g. if you see [2], and don't recognize it, but can draw it into the tool, you can get 而 correctly, without having to draw the very specific stroke order[3], like in other tools.
It's made for Chinese, but I often use it for Japanese, too. :)
[1] http://ce.linedict.com/dict.html#/cnen/home
[2] http://www.ryuurui.com/uploads/1/5/4/8/15489306/6738815.jpg?...
[3] https://upload.wikimedia.org/wikipedia/commons/2/2a/%E8%80%8...
• Last updated in 2012: http://shapecatcher.com/news.html
• No way to draw straight lines except pixel-by-pixel (really tedious). This turned out to be a pain when trying to draw various arrow types (made of straight lines).
I'm hoping the author, Benjamin Milde, picks the project up again and keeps it updated, or makes it Open Source, then someone else does.
(it found all the letters of the word "nice" quite well!)
Now that Python supports unicode identifiers.......