Anything and everything interesting - he's not to the point of capital-S Scanning the crowd, but mostly because he has noticed that if you put yourself out there in this place, someone interesting is bound to show up.

In this case, he keeps half an eye on Futaba as she approaches - her presence in itself doesn't startle him, but the words -

He recovers quickly. He'd been warned. But the surprise was still there, far more open and honest than that of the younger Akechis. He catches himself, to some extent, and the smile he gives her over his phone is mostly not feigned.

"And I never thought I would hear such words from my younger sister's mouth," he says, before stowing his phone. "Though if you were hoping to blindside me, I'm afraid that surprise in general was ruined for me some years ago."

It's nothing world-shattering to him. Just a painful fragment unresolved from a life he left behind.