Just like Aiko (who has an A3->SP figure), Hiro has an H3->D3 figure which has Hiro's head with all its morphs and David's body without morphs, but it can take the David Body Morph INJs and the whole thing can take David (and, I think, M3?) textures either manually or by MATs. And as Byrdie said, watch out for the new leg material zones.

Bought him earlier tonight, I'll start playing with him at the weekend.