You know I've had this kkir fic idea post-prison breakout for a while where Iruka starts to visit Mizuki while he is recovering in prison after Naruto goes away to train with Jiraiya. Pretty sure it's stated after that arc, Mizuki won't be able to perform any form of jutsu, and no longer will be a threat, so Iruka feels more comfortable visiting him on his own.
He doesn't visit him out of nostalgia or hope that he can help Mizuki. He visits him out of pettiness.
Listen, yes, Iruka might have grown out of his rebellious borderline delinquent phase, but he is very much still the mischievous prankster. Just more controlled.
Iruka talks about Naruto. Talks about his progress more like a proud teacher like a proud father, talks about anecdotes with Naruto, talks about how much closer they got after Mizuki's betrayal, talks about him as family, talks about spending time with Naruto and Hatake Kakashi.
And if it didn't annoy Mizuki enough to hear about the "beast demon child" he tried to kill and got his ass kicked by doing so much better and exceeding in life, to know everything he told Iruka that night he betrayed the village was wrong, the mentions of the copy-nin becoming a constant presence in Iruka's life hit a sensitive nerve. Of course, once again Iruka is the center of unearned attention from one of Konoha's most important shinobis. Fucking great.
And it annoys him horribly. It makes his skin crawl.
He likes to admit it or not, Iruka knows him all too well to push the right buttons.
If he feels this more whenever he hears a whisper in the back of his head saying just how nice things could've been for him if he had chosen that life, he never acknowledges it.
Oh, but it's something else entirely new when he notices the way Iruka talks about Kakashi begins to change. It's another level, it's not just plain annoyance. There's more to it than he can put his finger on.
It doesn't hit him until a time Iruka is retelling a conversation he had with Kakashi last week they went to drink together with others, Iruka smiles at whatever ridiculous challenge Gai came up and Kakashi accepted— he really isn't paying much attention—, Mizuki's gaze zeros in on the way Iruka scratches at the outline of his scar (a little action he's oh so familiar with) and lightly blushes.
It seems he wasn't the only one who noticed. Because the next visits decrease for a while, maybe once a month, he isn't too sure about how much time passes in jail. And when Iruka is back, he's always mentioning something that sounds awfully close to a couple of milestones between him and Kakashi.
Mizuki is almost grateful when Naruto comes back to the village so he can stop hearing about that fuckass stupid lazy copy nin. Though it's not like Iruka is dropping by as much as he did at the beginning of... whatever this is they're doing. It's like he's almost doing better. The thought annoys him.
Then Iruka stops coming altogether.
He connects the dots when word gets around between prisoners eavesdropping on guards' conversations about Pain's attack on the village. About the death of many shinobis and resurrection. About Konoha rebuilding itself from scratch. About the jinchuriki kid saving the village.
Almost ecstatic at the possibility that he may be able to take advantage of Konoha's weekend forces and shortage in prison security and get out. It doesn't happen.
Iruka visits again from what seems out of nowhere. Visibly tired and stressed. But trying to look well put together.
"You're here. Good". That's all Iruka says to Mizuki, wearing a troubled look before he shortly leaves.
The prisoners hear the declaration of a 4th War. Iruka doesn't come back. Mizuki is annoyed at himself over the bit of disappointment when he begins to rationalize that he won't come back at all.
The 4th War comes to an end. Time passes and Iruka visits him once again.
He goes on and on about closure, about new beginnings for Naruto, for his previous students, for the next shinobi generations, for Konoha, and for him. His words jump from realizations after the war, to the Academy and his new position as vice principal, to anecdotes about Naruto, Hinata, and Kakashi- his precious people, his "family" he says.
Mizuki welcomes that skin-crawling sensation with open arms at the implication of Kakashi being lumped with the pair. Eyes fixated on how Iruka scratches his scar like the first time Mizuki noticed that change between the way he spoke about Kakashi.
There's a particular pause after that and Iruka confirms what Mizuki tried to ignore.
"I suppose you already guessed, but if you didn't, I'll tell you outright. Kakashi and I are together, have been for a long while".
It doesn't prepare him for when Iruka announces this is his last visit. He wants to embrace all the new and focus on the people dear to him, mentioning that he once needed to give himself this tiny act of pettiness to showcase to Mizuki how wrong he was, how he failed, and threw his life away over nothing. Wanted him to experience even just a breeze of what the storm he felt was with his betrayal and prove he was okay and happy despite everything. He didn't feel he needed to do any more when, in the end, it was the same betrayal that changed everything for him and Naruto.
He wasn't grateful to Mizuki, not at all. But reflecting on the butterfly effect that shitstorm was, it let him let go of the hurt. He won't come back to it.
And he doesn't. No matter how much Mizuki yelled and hit his cell bars, Iruka didn't look back and never visited again.
That doesn't mean Mizuki never gets a visitor. On the contrary.
Time passes, and a guard wakes him up, announcing he has a visitor. His ears and eyes didn't believe it when they saw the person standing in front of his cell.
Clearly smiling under that stupid mask. Both eyes uncovered.
"You know, Iruka has really grown to be a wonderful person. He always was, but he somehow manages to better himself day by day. He used to tell me about his visits, and he told me too when he decided to stop, he wanted to leave his pettiness behind, but I'm sure you remember what he told you." Kakashi paused to leave room for Mizuki to say anything.
Mizuki scowls, not giving him a word, only glaring at him.
"Maa, you make it easy. He's always been the more mature out of the two of us, so I don't really care how it looks on me what I came here to do", smile clear in his voice Kakashi settles into place and in the way his closed eyes curl.
Kakashi raises one of his gloved hands, its back facing Mizuki. He makes sure to make eye contact with Mizuki before moving again.
His other hand pulls the glove up only to reveal the Rokudaime's pale hand, a shiny ring decorating the fourth finger. An engagement ring.
When Mizuki redirects his wide, seething eyes to the copy nin's face, he can see the smile behind that mask stretching.
"Iruka and I are married".
Mizuki tries to throw a punch through the cell bars, but it doesn't land. Kakashi dodges it with ease. It doesn't stop the waterfall of curses, insults, and more that comes from Mizuki's mouth, kicking and hitting with his fists at the cell bars. Shaking them as if it'll make them crumble down somehow.
Kakashi stands there, taking it all as if it were music to his ears, and leaves. Enjoying how Mizuki keeps throwing tantrums while Kakashi starts walking away with only one place on his mind.
