Gakutensoku

I'm Japanese, and this is the first I've heard of Gakutensoku. If you asked people in Japan for an old Japanese "robot", I think most would come up with this tea-carrying karakuri doll. https://en.wikipedia.org/wiki/Karakuri_puppet

That one predates the word "robot" entirely. The design is documented in a 1796 book called "Karakuri Zui", so Edo period, shoguns still in charge.

Automaton

The Wikipedia page doesn't say: what happened to this robot?

> the details of its disappearance are unknown

A mystery! Someone will know...