The routine started on just a random day. Akihiko had returned from his morning jog, and was able to start a conversation with you, for the first time.
Somehow, it ended with him roping you into joining him next time. And so, next time came. A run to and from the nearby shrine. You were, as he expected, half-dying afterwards, but he promised that it'd pay off in the end.
After all, this is just a form of training. It'll only make you stronger.
You joined him a few more times after that, until it eventually became a regular activity for you two. Your bond with him seems to be deepening bit by bit, through the small conversations that would occur whenever you'd stop.
It makes for good incentive to continue, it seems. Now that you've gotten past the stage of dying after every session, it seems like the perfect time to form a real connection with him, without him having to worry about your condition.
And so, this morning, you prepare for the continuation of this routine, just as he does. He meets you in the lobby of the Iwatodai dorms, as always. Just like usual, he's the one who's waiting for you. Not that he ever seemed to mind. "Good morning." Akihiko smiles at you, before standing up from the couch. At this point, it doesn't need to be said anymore. This activity has become second nature to the both of you. "Should we get going?" He asks, looking you up and down to check if you're in good enough condition to be running today.