He says that he wants to marry her, when they're seven years old.

The two of them are sitting on the floor in his room, Peko keeping an eye on the door in case someone comes in to kill him – even at seven she knows, she knows that if someone goes after him she has to jump in front, she has to die for him if she can't manage to get rid of the assailant – and Fuyuhiko is, as always, far too distracted.

She knows that it can't happen, it's been drilled into her head since she could walk that she is nothing but his tool, his means of staying alive and his means of killing those who oppose him. But, another of her jobs is to keep him happy, so she says "If you want to," and keeps her eye on the door.

"All the other girls are too…" he can't seem to think of a word and just shudders. Peko nods. Fuyuhiko adjusts his position and leans back against his bed, staring up at the ceiling. Peko glances at the window. They stay there in silence.

The next time they come close to discussing the subject, they're twelve years old and she is training when he pops up behind her.

"Peko," he says, and she turns to face him. It's night, and he should be asleep – she's just fitting in a little more training in a pair of shorts and a sports bra before she gets her own rest.

"You should be in bed, Young Master," she says, and he rolls his eyes.

"Cut the bullshit, Peko," he says. He's started swearing more and more lately. When she lets herself think those kinds of things, she thinks it's kind of cute. It's silent. She keeps flicking her eyes around, glancing at each entrance to this room in turn. "Remember that thing we decided?"

"Which one?" she asks.

He suddenly looks very embarrassed, eyes dropping to her newly developing, nearly unclothed chest, and she's suddenly self-conscious. She's been wearing this sort of thing to train ever since she started needing a bra, and only now does it seem strange.

"Where, ah, where we were…"

She has a feeling that she knows what he's talking and grabs her shirt. She pulls it on after taking one more glance around the room.

"Let's go to my room, Peko," he says, and she nods.

"Of course, Young Master," she says, following him to his room. He sits down crosslegged on his bed and she stands by the door. He's feeling awkward, she can tell, and somehow his awkwardness is spreading. She cares for him, she does as much as she'd like to suppress it or try and turn it into something that a tool feels for its master.

"You won't ever leave me, right?" he asks suddenly, and she's a bit shocked, to be honest.

"Of course not," she says. "I am yours forever."

"'Til death do us part," he says, a small smirk playing across his features. It's another one of those things that looks cute on his babyish face – once he hits puberty that will probably go away, and though it's another one of those things that Peko likes to pretend she doesn't adore about him, she'll miss it. He glances out the window and Peko, thinking that he maybe saw something, follows his gaze.

It's nothing.

Just the stars, which melts the smirk off of his face and causes her to get off of her guard for a few seconds. Once she realizes what she's doing, she snaps back to attention, and he glances at her.

He doesn't say anything, he just looks at her, and she looks back, not letting her gaze stray from his face. He looks oddly melancholy this evening, and for some reason she feels she needs to reassure someone that she won't leave him.

"I am yours forever," she says, and her voice is soft, almost too soft for her own ears to hear, let alone his, but he nods.

"Yeah," he says. "I know."

The third and final time they discuss the subject is before their death, with the execution looming over them and everyone surrounding them. He's panicked and she tries to reassure him and, really, though she didn't get to keep her word, at least he did.

I've never written this pairing before but it is super cute even though I'm still not sure on Kuzuryuu's characterization? Either way, this was written for an anon on Tumblr who wanted a Kuzupeko, pre-despair? There was a bit of despair at the end, but since the majority of the oneshot is pre-despair, I decided that it worked.