seki108

Just remembered earlier this canonically exists in Touhou. 

However, this mighty beast is actually a hot air balloon.  It was one of the few people with outside world knowledge that saw it as a mecha in the side game it debut in.

Despite this limitation, it seems Hisoutensoku gets to become a full-fledged robot in the last Fantasy Maiden Wars game.  I'm still a long ways from there, but that will be awesome.