(Note) The following setting is purely my own imagination.
Machu discovered the motorcycle his great-grandmother rode on Earth when she was young, and commissioned Kaneban Co., Ltd. to restore it, bringing it back to life. (At that time, Mr. Jezzy put stickers on it without permission.)
Incidentally, the voice of his great-grandmother from her younger days, which was recorded on a storage medium, was said to be very similar to Machu's voice...
Machu's body was assembled straight out of the box, with only the seams of his uniform jacket being treated.
The motorcycle was fully painted.

Machu who commutes to school by motorcycle | MEE's Gunpla works