I don't think Aki stayed behind... Look. He hops out of the vehicle. Maybe he's creeping around somewhere? He's sworn to watch Asami's back to himself.
Edit: Plus the "Always keep your eyes on me." "I understand." Maybe Asami knows he'll follow anyway and was in a roundabout way hinting for Aki /not/ to stay put.
I don't think Aki stayed behind... Look. He hops out of the vehicle. Maybe he's creeping around somewhere? He's sworn to watch Asami's back to himself.
http://www.mangago.me/read-manga/you_re_my_loveprize_in_viewfinder/mh/iur_chapter-85/pg-10/
Edit: Plus the "Always keep your eyes on me." "I understand." Maybe Asami knows he'll follow anyway and was in a roundabout way hinting for Aki /not/ to stay put.