What is Astro's last name? Tenma? None needed?

[AprilSeven]

Good point . . . and yet . . . Astro is part of a family (two parents, two brothers and a sister). Families generally have surnames to identify them, so it would make sense they'd have a last name. It would odd if it were "Tenma" as only Astro (and Cobalt, depending upon the story you choose for his creation) were Tenma's robots.

I guess they could actually use Ochanomizu/O'Shay/Elefun as Elefun basically "adopts" Astro and built all the other robots (including Cobalt, if you consider that version of his birth).

Jeffbert had a clever idea -- referring to them as the Tetsuwan family.

It's true -- he doesn't "need" a last name (he's kinda like Madonna!) but it seemed appropriate as a robot striving to be as human as possible, Astro would have a human-style name.