If you want another kid that Tenpou might recognize, Kou's family is influential enough that he could have been hanging around the Tokyo shatterdome from time to time as well. Not as frequently as anyone whose parents would have been staff, just along the lines of when important meetings might be taking place. He would have been 11 when the Kaiju attacked and 12 when the shatterdome was established.

He's a snarky, playful kid but he has a good upbringing so he wouldn't have caused any trouble. Sorry I can't offer you any actual co-workers or anything. But if you're interested we can come up with some silly interactions they might have had.