Mayuri has always been his closest friend. He doesn't even remember their first meeting, only that she has always been one of life's few constants. No matter what happened or what worldline they were on, their friendship was unchanging, comfortable, perhaps even destiny. They had been friends so long they could almost read each other's minds, so he'd assumed that she knew how important she was to him. He had never said it out loud; Mayuri was smart, after all, and surely she couldn't miss something this obvious.


They are standing on the roof, having quiet conversation in the calm before the storm when Mayuri shatters his naiveté. "I guess you don't need me to be your hostage anymore," she says, and Okabe comes to the horrible realization that Mayuri has no idea how important she is, to him, to the world; he makes up his mind to say something, anything, to reassure her that of course he needs her, will always need her, and anyone who says otherwise is lying. Kurisu interrupts before he can say anything, and he vows to tell her as soon as he can.


As soon as he can, however, turns out to be a long time away, at least that how it feels to him. Mayuri dies, and dies, and dies, countless times. There's so much blood, and he doubts he'll ever sleep peacefully again, his mind full of her blank eyes and broken body and he's screaming for her, but there's no answer. She's gone.

The worst part is when she talks about finally being useful, because he wants to scream, to her, to the whole world that there has never been a time where Mayuri hasn't been useful. That she is so valuable to him simply because she's his best friend, and the best person in the whole world. But he's too late again. He vows to tell her, as soon as this entire mess is over with, because this has gone on for far too long.


When the world has finally been put to rights, he almost forgets his promise, because he's too relieved that Mayuri is alive and breathing and happy and not hit by a car or run over by a train or dying in any number of horrible ways that he doesn't want to remember but can never forget. He remembers, suddenly, when they are walking down a crowded sidewalk. Mayuri is holding his hand and smiling, giggling as she talks about school and the maid café; he stops abruptly, and tugs on her hand so she faces him. She looks confused, cocking her head at him. "What's going on, Okarin?" she asks, as the people around them are forced to stop to avoid walking into them.

Okabe doesn't care, doesn't even notice them. His focus is only on Mayuri, and making sure she knows just how amazing she is."Mayuri," he begins, his voice serious for once. "You know that, no matter what happens, or how many other friends we have, I will always need you. You will always be my hostage."

Mayuri tackles him in a hug, and her smile is brighter than ever. "Of course!" she responds, but she looks happier than she's been in weeks, and there is a new skip in her step when she tugs him forward, rambling on about what cosplay she's making for her next convention. Okabe thinks that he should have told her that a long time ago.