Kakashi grows older and taller but stays beansprout thin, his bony shoulders swamped by the smallest sized flak jacket the exam proctors can find him. He hangs it carefully in the rickety cupboard of his second-hand apartment and dusts it now and then while eyeing it with silent, thin-lipped determination.
He survives on three wolfed-down meals and wears himself out with an equal number of training sessions a day. When night falls, Kakashi curls up with a book, his drooping eyes tracing the text as he absently wriggles whichever loose baby tooth he has.
(And if Kakashi sometimes stares at his reflection, stretching his lips in a grin as he sticks his tongue between the gaps of his teeth, Sakumo won't tell a soul.)
With all of Kakashi's unnervingly blank stares and masks both physical and metaphorical, friendships don't bother themselves with him. But Eternal Rivalries do and Sakumo has never been more appreciative of green spandex and orange legwarmers.
Kakashi needs all the supporters he can get even if he doesn't realise it. The older chuunins ostracise the prodigy amongst them and the deeper the inferiority complexes, the crueller they are.
"Missing daddy?"
"Aw, it's alright. You're better off without him."
The taunts are weak and uninspired, but it doesn't stop Sakumo from sending his disembodied foot flying through their sneering faces. It a cheap shot and doesn't make them do anything more than shudder and sneeze, but if that's what Sakumo has to work with, he'll make them think they have the worst flu in the Konoha before they say anything to his son again.
Kakashi looks at them quietly, all hidden canines and narrowed eyes, snorts out a "yeah" and shoves past their surprised faces.
Smiling crookedly, Sakumo just plucks out another shard of his heart, places it together with the handful in his pocket, and trails after his son with pride twisting beneath his sternum. Kakashi is strong, stronger than Sakumo ever was. He's not about to become anyone's doormat, no matter what example Sakumo set.
The name White Fang becomes a mere footnote in conversations as the village turns to newer gossip, revelling in fresh scandal and misery. Unable to sleep in this ghostly form, Sakumo spends the lonely hours of the night perched on the windowsill of Kakashi's apartment, watching the citizenry stumble drunkenly home, laughing and joking with arms around friends and lovers.
On darker nights, when Kakashi is tossing in the grip of nightmares and mumbling half-formed pleas, resentment pools and festers in Sakumo's stomach. He should have never given any of them an ounce of his consideration. Yet for all he tries to hold on, the sour burn of anger evaporates into fumes before long, leaving Sakumo drained and weary.
The burden of blame isn't so easily shifted, especially not onto people like one Minato Namikaze, who has the sun in his hair and the sky in his eyes.
Jiraiya's ex-student becomes Kakashi's friend first and jounin-sensei second. Minato wrestles Kakashi into ramen dinners at Ichiraku, lets the boy into his apartment to borrow books, and tucks a blanket around Kakashi when he falls asleep on the couch. No ninja worth his salt wouldn't wake from someone hovering over him but Minato lets Kakashi pretend. Come morning, Minato hums and smiles as he eats Kakashi's home-cooked breakfast like the "thank you" it's meant to be.
For the first time in a long, long while, Sakumo can breathe. For everything he failed to be, maybe Minato can be instead.