He's surprised that Idia's so willing, but then he realizes that he's also lived a lonely kind of life. And here? He didn't have those obligations. No social heirarchal bullshit. There'd be nothing but good intentions in coming to see him, and he knows that, and there's not enough of that in this boy's life. They'd just be showing up, wanting the time with him, mostly at their own expense.

Except for this. His contribution. His effort to see them again.

"I dunno, to be honest. Other'n Voidtrecker. And I remember some of them snack brands you and Kyoko used to eat. I'd help her order 'em sometimes."

So yes, this man could respond to a password that involved Pocky or Calpis or "Hello Panda". But it's the best he could come up with on the spot.