[ If he had to give it a deliberate thought... ]

Honestly? There's one reason.

[ He shifts a little, and looks back at the conked out form of his older brother on the bed. ]

You share his headspace, you're an older brother to him the way he is to me. I don't know you very well outside of the files.

[ That is the most indirect "I want to get to know you better" he has ever said in his life, Makoto. ]