Yuya nods, not intimately familiar with war and rankings and any of that. But he thinks he's following along.

"So you work with them? To fight the, uh," he pauses, trying to remember what 9S told him before they entered the arcade. "The machines?"

The tone he says it in, it's clear he has no perception of exactly what the machines are. Cars are machines. 9S is technically a machine. 'The machines' sounds like something he'd see in an anime. What exactly are they?