Rei can only watch, frozen, as Airi takes on the meanest of the neighborhood kids with all the earnestness of a four-year-old with a loud voice and sharp teeth. They've been at the park until now, feeding the birds and getting chased round by the swans, and in the safety behind the park benches earlier he'd asked: mother and father don't know yet, but I want you to call me your big brother, all right? Airi's believed him more than he does himself, and he cowers until the adults break things up.
His mother takes her aside, explains how ladies do not use such words (and they certainly do not bite people, either). Airi nods her head, promises to behave, and follows his tormentors around telling them in the most carefully chosen polite child's terms all the things they're free to do to themselves if they call her brother a girl again—involving spiders, or snakes, or maybe even centipedes which are worse because they're spider-snakes—and how she's far too much a lady to do such to them herself, you understand? They tire of picking on him, and Rei swears on the spot (cross my heart, all that stuff, sis) that he'll back her up in return.
From that day on, nobody messes with his little sister.
Their parents scold him too, at first, and Rei fights them even harder over the very words Airi takes pride in. "I'm not like her, I'm not going to be a lady"—he says it over and over until they have to believe him.
Months later, he presses his ear to the wall and can hear them discussing how to handle such a problem child, all hushed tones and loanwords and terms he doesn't understand. "The doctor says to humor Rei for now," he hears last. "She'll grow out of it, most of them do. It'll be okay." Rei almost shouts back that it won't, not like this, but bites his tongue and crushes the pillows instead.
The next morning, there's silence on the topic he so wants. Who and what he wants to be just isn't discussed, and he's satisfied with the illusion his parents understand. What feels weird is how when he gets into fights with the old bullies, nobody questions it; in fact, his dad shows him how to throw a punch ("I won't have you breaking your fingers defending yourself," he says), one of the first times they really talk since that night. It's hardly fair, Rei says afterwards to Airi, when you were kicking their asses just as well as I was. She tells him no worries, it's just the way things are. Indeed, she works with words in a way he never manages, and is the one who later charms their parents into letting him study the Nanto arts as something other than one of the rare female students.
Here, Rei finds for the first time a sense of belonging. Fighting is a matter of honor, not squabbling; when his teachers speak of strength as a way to protect, that belonging gains purpose. In learning he disciplines his mind, controls his body through the changes testing his resolve...and it's enough he is content. Any teasing he gets is for being a momma's boy (actually, it's sister's boy); even when his voice refuses to drop farther than he can teach it and he leaves his hair long, it's just "prettyboy".
He takes those words and he turns them around, becomes light on his feet and sharp in his hands. When asked where such grace comes from, Rei only smirks.
It throws him, briefly, when one of his mentors steps down from the successor's candidacy for the sake of love. Lady Rinrei's fine techniques have been the ones he most envied, her kindness in teaching the boy with the odd center of gravity one of his comforts in his early uncertain days...but she would rather be by his master's side than follow the Suichou Ken successor's path alone. Rei no longer questions other people's happiness when he has his own, and so he congratulates her, continues to study what she and her now-husband teach. What little unease remains melts away under years of hard training, and students never guess what his family still don't speak of.
At the century's end, his loyalties are unwavering even while his life is in chaos. Let the other Nanto masters sort out the world, he seeks justice for Airi. Revenge, if that's all that remains. The bitter road he takes grows single-minded, selfish, but if he cannot protect the first person he swore to, he sees no point in caring for any other.
Meeting Mamiya throws him off. She welcomes him and Ken as protectors, but makes it clear she means it's for the village's sake and not her own, and she keeps tears for her brother to herself. A strong leader for a harsh world...oh, this he can admire, but in her kindness he sees the woman she's forgotten—one who does not deserve to be dragged into fighting and dying at the hands of the vermin hounding her home. Mamiya will have nothing of his concern, and follows Ken and him into the wasteland like the fighters he grew up alongside. As they sit by the fire and wait for the Fang Clan's attack to come, Rei would call her stubborn...and his mind lurches when he recalls his parents saying the same of him.
He has no time or thought to spare on the point once Boss Fang arrives with Airi in tow. His world narrows to that promise years back, and he struggles against Ken holding him back as they face down the beasts' boss. "If Mamiya can help save my sister, then I will owe her my life," he says of her plan, gets Ken to go along with it and the further desperate fight that follows. As Mamiya made good on her word, Rei vows to keep his.
That makes two people he will die for.
Rei limps off to recover, and he and Airi settle down in Mamiya's village as if returning home. Ken resets shoulders, helps bandage hands, even restores vision, and their group bonds over injuries and recovery over the passing days. The village duties Rei volunteers for soothe a sense of purpose survival left empty, and its people...alongside them, through them, Rei remembers what it's like to feel human. In the nights, he has space and peace enough to think, and sprawls out on the rooftops to let the wind run through his hair.
He picks through emotions and moments grown hazy from distance, finds the ones that still ring in his mind and draws lines of before and after the fallout from that day in the park as razor-edged as his nails. No one here will judge him for the parts he still sidesteps. They don't even ask, even days and weeks later when he slips unguarded enough Mamiya reads him on her own and they talk over coffee. It's a leader's intuition, not a woman's, she says, and offers him another silence.
There is no one left who will judge his worth as a man other than people he's come to call dear friends. It's easy enough to say he'll fight for them, protect them (a reawakened man of justice is everyone's champion, just as Ken is everyone's savior), but admitting how much character he shares with Mamiya herself is a hell of a lot harder. They spend many days traveling by Ken's side, further time tracking down respective Tokis, and Rei's respect and feelings come unspoken. He has his excuses, she has her reasons, but their growing closeness is never a topic they breach.
The last time he speaks to her, it's still coached in old learned words. "Be happy", he manages at the last, and hopes his life is payment enough that can be true.