Gen was used to that face - if he went around acting like a fool so people discounted what he said, he needed to be used to people thinking he's not smart. The kid was much more polite about it than most fourteen-year-olds were, too. It helped, of course, that Nico's angle was one that Gen would usually be arguing.

He's usually the realist who had to bring people down to Earth.

On this subject, however? Gen smiled, something genuinely fond coming through, when he said, "If Senku-chan can stubbornly insist on trying to save six billion people ... I can stubbornly throw in my efforts to save just one. I'm being lazy in comparison, hm?"