[ even though he looks happy, a flash of worry and doubt crosses his mind when Aoba mentions gratitude. he mostly does things for aoba without expecting or even the other noticing, but he doesn't want aoba to think he's not grateful. he won't talk about it, but he'll make a mental note of it. ]

Oh? [ he says in a teasing manner. ] You make a good argument. [ it seems like aoba has won... or has he!? ] Fine, I'll teach you how, but under one condition. [ he pauses, looking at the car. ] No more practicing alone for now. Is that fair?