You don't know you're different until Marisa says she is, when you are still young but growing up. Marisa wasn't assigned female when she was born, but she's started to transition with magic in the last year, around the time your own body started to grow. But unlike Marisa, you don't have magic, and you don't know what you want your body to look like until it has already become something you don't want.
Marisa, as is typical for her, is trying to turn your chest development into a competition. And you know you should be happy for her, getting to have what she wants against all odds, but you just wish she would leave your own body out of it.
"Look at this," she says, the day after you switch from your winter clothes into the looser spring ones. "They're bigger'n mine." She pokes at her own chest to demonstrate. "You're lucky."
Lucky? To have these things you don't even want? You snort, roll your eyes, ignore the sting. "Shut up."
Later that night, after Marisa's gone, it hits you again. You hate it, you hate it so much and your breasts feel like deadweights choking you with every passing second. You can't handle having them, not when they feel so wrong, and you hate them and you hate yourself and before you know it you're topless on the bathroom floor winding a sarashi tight around your chest.
It's hard to take deep breaths, but you've had worse. You put your hand against your collarbone and run it down, and it's flat until you reach your belly. Completely flat with no trace of those things you can't stand. You scramble to your feet, turn sideways in front of the mirror. No breasts. You pull your shirt back on and look again. They're gone.
You unwind the sarashi before you go to bed. Your chest feels sore, and you feel so strange taking deep breaths, but it doesn't matter. You figured it out, and you felt so much better with the bindings on, so much that you'd almost forgotten they were even there. For the first time your body felt normal.
When Marisa sees you bound the first time she notices right away, not even saying hello first. "Reimu! Where'd your tits go?!"
You feel an odd mix of disgust and pride. "Under my shirt?"
"Yeah, but like, you're flat."
You breathe in, feel the wraps comfortingly tight against you. "I bound them down."
"I don't want them," you mumble awkwardly.
Marisa seems unfazed. "Oh, well, I'll take 'em. Can't grow boobs on my own, y'know? I need all the help I can get." Is that a hint of bitterness in her voice? You can't tell.
"I wish you could," you say.
"There are like, body exchange spells, but I dunno if you can only do one part, you know? I might end up with your feet or something."
"Let's not risk it." But somewhere inside, you want to. You don't want this body that feels so foreign and wrong. You don't want to be a girl anymore.
Yukari likes to hang around your shrine on the warmer days, drinking from a sake bottle she pulls from nowhere. She's just woken up from hibernating, and doesn't seem fully awake most of the time. Which, in fact, doesn't stop her from being irritating nonetheless.
"My, Reimu," Yukari says, fanning herself. "You must be hot in this weather. Especially with bindings that tight."
"I'm managing." Your chest does feel sticky and sweaty under your bindings, more so than usual, but there's no way you're going to let Yukari know.
"Managing isn't as good as thriving."
"Do you need something?" You're easily fed up with Yukari on the best of days, and this is less than a good day.
She smiles behind her open fan. "I merely came for a visit."
"Great." You usually try to ignore her, but she can be irritatingly persistent, so giving terse answers usually does the trick instead.
"So. About this," she says, drawing a hand over your chest suddenly, but not touching you. "Is it uncomfortable?"
"No." It sort of is, but not enough to outweigh the comfort it brings.
"What caused you to do it in the first place?"
"I felt like it," you say, which is the truth.
Her deep purple eyes, as always, are searching for something more. It's unnerving, the way she stares into you like she's trying to read your mind. "Gender dysphoria," she says, after a moment.
"Do you feel disconnected or uncomfortable with your body?"
You don't want to let her know, but that's exactly what you feel, down to the letter, and it's so terrifying that Yukari is right.
"Many people have been in the same predicament as you," she continues, without waiting for a response. "Kirisame Marisa, for example, and myself, though I changed my entire body long, long ago."
"Why are you telling me this? And how the hell do you know about Marisa?" you ask, frustrated.
Yukari smiles even as she sighs. "What I'm trying to tell you, dearest Reimu, is that we are not determined by our bodies, or what others think of us. Are you quite sure you're a girl, now?" She doesn't answer your second question.
"Leave me alone," you mutter, looking down into the dirt.
She shrugs. "Suit yourself." A gap opens up, and she's gone, leaving only the faint trace of the smell of lavender.
You fucking hate Yukari.
But maybe she's right, even if you don't want to think of the possibility. Maybe you aren't a girl. But you don't know what, then, if not female. Not a boy, definitely. In between? You dismiss that quickly. What else is there, though?
Why not just be nothing?
You lie awake at night thinking about it. The more you consider it, the more it feels like you. You are not a girl or a woman or a maiden, despite what your body and your life and your position in Gensokyo says. You are nothing, nothing at all, and you exist. And it fits.
"I'm not a girl," you tell Marisa the next time you see her, and she wraps you into a hug and says she's so happy. "You look so comfortable saying that," she says, and there's a smile in her voice. "I know how much it means."
For the first time, you do too.