alt Hacker NewsIt doesn't seem to me like they trained it to write Japanese characters, but more broadly to reproduce a drawing or pencil strokes, so I don't think it is extremely surprising.
"Their learning system is split into two distinct models. A “local” model is in charge of what’s going on with the current stroke of the pen—so aiming in the right direction and determining how to end the stroke. And a “global” model is in charge of moving the robot’s writing utensil to the next stroke of the character."
From the paper: "To generate sufficient amount of training data for our model in simulation, we use KanjiVG [5], a database of Japanese Kanji characters. This database consists of both images of the character as well as an ordered list of strokes in the SVG format."