It's in the little moments. The times they have each other's backs in tight spots, or when they're sitting around a campfire, joking and choking down food rations. It's the hand on a shoulder before watch duty, the way they can beat the crap out of each other training and go, exhausted, to dinner afterwards.
Sometimes it's in those stray moments they carve out to miss Sasuke. The knowledge that he didn't die, wasn't taken from them – that he chose to leave all this behind puts a bitter, acrid taste in her mouth.
Each encounter thereafter has been a more and more bitter pill.
"You know," Sakura says briskly as Naruto trails after her on her hospital rounds, "You're my best friend."
She can see him staring at her, wide-eyed and surprised, because he'll never get used to the idea that people might actually like him. Her heart could break on that expression alone. Naruto deserves so much more than the hand life dealt him.
His smile is a slow sunrise, calm and wise and warm. Peaceful, like all he could ever want in the world is in his hands waiting for him to notice.
Easily, he replies, "You're mine, too, Sakura!" and tries for a hug which she ducks out of, rapping knuckles lightly across the top of his head.
She's smiling, but when she turns back to her clipboard her gaze thins away into something more steely.
She loves Sasuke. And she knows without a doubt that she'll kill him before he ever hurts Naruto again.