Shirogane sets him on the couch as Aria-shachou continues explaining, obviously still excited and not at all worried that Akari didn't understand him right now. She would eventually understand! He believed!

Shirogane in the meantime had ceased listening, and is instead thinking back on the e-mail. Not to reconsider sending Kou to Pluto, of course. That wasn't up for discussion.

But 'practice makes perfect.'

He looks at Akari again before crossing his arms over his chest and thinking some more.