Minato notices it since the first time he meets up with Sakumo and his new (first) student: Kakashi doesn’t like to be touched. It’s in the careful space between the six year old and his father. Minato knows Sakumo in passing, their circles not intermingling much, aside from a few celebrations after a successful mission, and if there’s something that sticks out about the man, it’s his cheerful disposition and frequent touches (pats, hugs) to his friends. Minato can’t believe he wouldn’t behave the same way with his son if only Kakashi would let him.
So Minato is careful to keep the same distance with his student: Kakashi may be young, but he’s not a child and deserves to have his personal space respected. It’s hard, Minato has to admit; Minato, like Sakumo, is a touch friendly person and likes to communicate and reassure with a hand on an arm, a pat on the back.
It’s even harder with a student. Not that Kakashi needs a teacher to lead him, but there’s a reason that the Sandaime has thought of assigning him a teacher and has chosen someone like Minato: Kakashi still has things to learn, but he needs to know how to be a normal person. Minato likes to think Kakashi can be a six year old, sometimes.
In short, Minato has his work cut out for him and without some of his preferred means to do it. Sometimes respecting Kakashi’s personal bubble is one of the hardest parts of his day.
Then one bright, crisp day of autumn, Minato goes to collect Kakashi at his home for an unexpectedly assigned mission and he finds his student kneeling beside Sakumo’s body. He reacts without thinking: he drops on his knees beside his student and gently touches the boy’s elbow. Kakashi’s arms are bare, because Kakashi likes his uniform that way. Lightning passes suddenly through the point of contact and Minato gasps in the heavy silence of the room, eyes widening.
Kakashi freezes, then his head darts to the side, eyes huge and dark and still glistening with tears.
Warmth is still spreading through Minato from the touch, as is happening to Kakashi. Minato’s brain is still trying to catch up to what has just happened, to what has just been revealed, when Kakashi darts forward and collapses into Minato’s chest, embracing his sensei tightly.
Slowly Minato hugs Kakashi – his soulmate – and Kakashi squeezes him out of pain and desperation.
Minato leans forward, until his lips are in silver, bright hair.
“I’m here. I’m here.” he whispers and holds on tight.