Disclaimer: Kishimoto's, not mine.
I just made this because I felt like writing more angst, and KakashiRin needs way more writing done.
Maybe in the Next Life
Shortly after Obito's death, Kakashi found himself holding a sobbing girl for the first time, and actually caring. He didn't realize this till much later, as he was grieving too. He knew then, that she meant something to him, but for all his genius couldn't define that something.
At age 14, he joined ANBU, on recommendation from his sensei. He excelled, he killed, he obeyed and he commanded. He believed it was the best way to protect Konoha, and by extension, Rin. He believed that it would give him some space, some distance to think and clear his head. Rational thinking escaped him, his thoughts would drift back to her at every spare opportunity, and he remained perpetually confused.
Eager to see her again, and his sensei, he rushed back after a particularly isolated and lengthy mission. He came home to a half-destroyed Konoha, the knowledge his sensei had died, and a sobbing girl. He held her again, and tried to hide his tears so as to remain strong.
She still knew. And he still hid.
He left not long after, on yet another mission on an endless list. She stayed behind to rebuild the village, and heal as a medic.
At age 17, his workload had decreased dramatically, and he decided to become a reserve, and become a regular J onin. She smiled happily at his announcement, and he felt a warmth creep up into his chest.
His days not spent on mission quickly fell into a routine. He would visit the hospital, and walk her to lunch. In the evenings, they would spar, and once exhausted take some flowers to the memorial.
Their friends questioned why they were not going out, when they were as close as a couple. He surprised them all by kissing her, his ubiquitous mask down, in the middle of the street. He smirked and she shot him an amused look with a hint of admonishment. Kurenai made the connection first, after seeing how easily they slipped into that kiss without any awkward nose bumping, and the looks that those two shared, that they had been going out. As she opened her mouth, a puff of smoke replaced the area that the two were standing in.
It took him months after they were together to convince himself to sleep with her. He wondered briefly if it would taint her as he had tainted so much earlier. She shot him a glare when he voiced this comment, and quickly pulled him into her bed. As she lay under him, moaning and sighing rather blissfully, he considered kicking himself for not doing this sooner. He joked about it as he lay next to her, after the act, and she pulled him for another round to rectify the mistake. He would sometimes wake up in the night, remembering too much. Obito, his sensei, and the terrible things he had witnessed in ANBU. She would comfort him, and a single hand on his back and a hug would erase everything from his mind. He knew he was safe, if only while in her presence.
He went on missions with her, and if she noticed the extra care he treated her with, she never mentioned it. Regardless, she was severely wounded once, and he stayed at her bedside for a week, hardly moving. She made him a promise then, that she would wait for him in the next life too, if he would have her. He blanched at the thought of her dying and silently prayed that his death was before hers as he hugged her close to his chest. She recovered quickly enough, and his heart settled down from the fear.
At age 20, Kakashi lost the reason his heart kept beating. She had died in his arms, and he had felt absolutely powerless. His entire existence, for it could no longer be considered a life, was bleak and dreary. Asuma, Genma and Gai had noticed that the amount of alcohol he consumed was double what he usually had. He had also asked to be reinstated into ANBU, and was constantly on solo S-class missions. His friends wondered every day, if that was the day they'd lose another in their number, to go with their beloved Rin.
At age 26, Kakashi was assigned to a team of brats, forced unto him by the Hokage himself. He couldn't decline. As he watched the two boys bicker and the girl try to act as moderator, he couldn't help the small little smirk that came to his lips. His existence just became a bit brighter, though it wouldn't be enough to make it a life.
By age 33, Kakashi had managed to watch his team grow up, with mistakes, Sasuke, and successes, the other two. He figured that his life was better for having known all of these young ones, and for having some influence on shaping his world. The added bonus of being Rokudaime while Naruto was yet too young furthered his sense of contribution. The hole in his heart still remained, however, and it couldn't be easily fixed.
At age 35, Kakashi found himself with a sword piercing his chest, his eyes unfocused and all his enemies dead at his feet. He could hear Naruto, Sakura and his longtime friends screaming at him to stay awake, to stay alive.
As dreams and reality mixed in the haze of his mind, he whispered, "I never managed to love you enough Rin. Not in this life. Maybe in the next life, I'll show you just how much you mean to me if you keep your promise."
This time, he was coming home. He was coming to her, and felt like rushing. Thirty-five was far too old for a ninja who just wanted to be with his soulmate.
This time, he was at peace; finally fulfilling all that he had left to do and now could obtain his only objective.
This time, he was never going to let her go. He was going to hold on tight to her.
As he closed his eyes, his friends let their tears run freely.
Genma and Gai, the last two of his four best friends as Asuma and Obito were gone, sighed and looked over at the memorial stone. The spot next to Rin's name was no longer going to be empty. And then they smiled, one that was bittersweet, their friend had finally gone to reclaim his love.