"Begin," Iruka says.
The room obeys like a door that always meant to open. Benches hush. Paper stills. Izayoi does not rush. He lets others leave first and steps into their space after it has decided to be a corridor again.
The hallway is bright where windows run its length and quiet where corners fold light back on itself. Floorboards speak in polite squeaks. Two teachers pass with papers held flat. A third adjusts a stack by the hip the way a person does who prefers order to speed.
"Hands visible," Iruka says from ten paces back. "No seals called. Hinata - eyes active."
"Byakugan," Hinata breathes, and the pale takes her eyes the way a lens takes distance. The veins at her temples rise and settle like a map that does not need to be read to exist.
Izayoi lifts his palms to chest height. No hurry. No posing. He takes the window plane - the strip where light falls in rectangles - and treats it as if chalk had decided to be glass.
"One word per action," Iruka says. "Hinata, you speak it when you know it. Everyone else watches feet and shoulders. Naruto, you count for yourself, not for the world."
"Yes, sensei," Naruto says, louder than needed and still learning the cost of sound.
Izayoi sets his breath where the after will be. A teacher with papers moves left to avoid a boy who forgets that hallways belong to all. Izayoi edits by a shoulder's width, not a step, and lets the teacher's path remain a line.
"Choose," Hinata says, voice small and steady.
He trades places with the air just behind a filing cabinet edge and returns to the light. No bump. No brush. The corridor does not notice he was anywhere else until he is already where he meant to be.
"Thin," Hinata adds, when the flow along his skin lands where it needs to.
"Good," Iruka says. "Keep palms up."
He does. The window's rectangles run like stepping stones for eyes. Izayoi treats them as notes on a staff - time more than place. A boy with ink-stained sleeves swings too wide at the corner; Izayoi is already not there. A girl carrying a plant like a trophy guards dirt that would prefer quiet; he gives her that quiet for free.
"Place," Hinata says, when his ankles fix the ground they have not yet met. She does not waste more words. Words cost breath. Breath buys timing.
They approach the stair landing where light slants and the rail interrupts the smooth line of window and wall. Iruka closes three paces without crowding. "Constraint," he says. "From here to the bend - one palm on the rail. Ankles honest. Edits only at the shoulder. If your palm leaves, you pay with five when we return."
"Yes," Izayoi says.
Hinata's eyes attend to small things. "Ready," she says, which means she has enough breath to say it.
Izayoi sets his right palm on the rail. Grain gives a soft complaint under skin. The corridor tightens where the stairs begin and the day changes angle. A teacher climbs, a stack of papers riding a stale breeze; two second-years descend with exam faces trying not to be faces.
"Move without moving," Iruka says. "Let them pass. Shoulders only."
Izayoi lets his shoulder be thinner than its habit. One of the second-years passes close enough for soap smell to consider being a fact. Izayoi does not give ground. He gives shape. The rail stays under his palm. Ankles choose one place and refuse all others.
"Edit," Hinata says.
He edits. Papers breathe past his cheek and become someone else's problem. He keeps the rectangle of light as a home base his body does not need but his mind prefers.
A low squeak crawls up the stairs - a small supply cart being asked to do too much with a short wheel and a long wish. A chunin with a list pulls it by one handle and reads while walking. The cart takes the corner wide. Naruto's group drifts wide with it, all good intentions and elbows.
"Izayoi," Iruka says, and the name is instruction enough.
He keeps the rail. He keeps the window line. He becomes the exact size of the gap that exists when two moving things think they are alone.
"Return," Hinata says, when the cart's wheel finally finds honesty and the list discovers stop.
Naruto appears at Izayoi's left by choosing enthusiasm over geometry. His hand hovers, not a grab and not not a grab. Izayoi offers a sleeve without offering himself and lets a polite touch land with zero cost.
"Thanks," Naruto says, surprised by gratitude coming out in time.
"Keep your feet," Iruka says. "If I have to look down to correct you, I am not reading the corridor."
"Yes, sensei," Naruto says, and then whispers to Shikadai, "Feet," as if invoking them would fix them.
Izayoi touches the corner post at the landing with the back of his knuckles the way some people greet shrines - a quiet hello that asks for nothing. He keeps his palm on the rail as ordered. A first-year from another class bolts up the stairs with papers that want to rebel. One catches the air and thinks about being a bird.
The paper sails toward the middle stair. The first-year reaches for it without thinking about weight or balance or where legs become edges. He stumbles on a lip where wood forgets to be floor for half an inch.
"Receive," Hinata says, the word leaving her on instinct.
Izayoi does not step. He takes the boy's arriving weight into the crook of his elbow the way a door takes late sun - by existing in the right place at the price of nothing. The boy's shin misses the stair edge it wanted to learn a lesson from. His papers come home to chest and stay.
"Sorry," the boy says too loud.
"Mind your feet," Iruka answers without heat. He hands the boy the one paper that chose wind. "Mind the corridor."
"Yes, sir," the boy says, and scurries with the humility of someone who felt a bruise that did not have to happen.
Izayoi puts his palm back where it never left, which is a trick you can do if you mean it first.
Hinata's one word arrives after she watches the breath leave all involved. "Place."
"Good," Iruka says. "We go to the bend. On my word - no words."
They go. A pair of older students argue in low tones about a formula that insists on being a problem. A shoji screen at the corridor's turn stands open a hand width - gap that wants to catch sleeves. Izayoi makes his sleeve the sort of wall gaps do not know how to love. He passes. The gap does not learn anything new.
At the bend, Iruka lifts his hand. The group stills without stalling. He lowers his hand again. The drill continues on the side where light falls less. The rectangle notes are grayer here, less obvious. Izayoi likes them better that way.
"Quiet," Hinata says, which tells Iruka what he needs to know. He can trust the corridor to be the teacher.
Mizuki appears at the landing with a clipboard in the crook of his arm. He does not step into the drill. He lets the drill notice him.
"Iruka," he says, small nod, voice that belongs to processes, not to interruptions.
"Later," Iruka says, which is not a dismissal. It is a schedule.
"Understood," Mizuki says, and waits where standing is not a tripping hazard.
Iruka adds a new line feathery light. "From here to the water alcove - no shoulder edits, only rib edits. Palms still visible. If ribs fail, pay five in the alcove."
Ribs learn what obligation feels like. Izayoi makes the corridor narrower inside his own body and walks that smaller room where bumping is a moral failure and not an accident. He reads a fabric flutter and lets it be a weather report rather than a reason to announce himself.
"Edit," Hinata says, when ribs have finished being a hinge instead of a story.
The supply cart returns the way poor ideas do - louder, armed with a new angle. The chunin has abandoned the list in favor of the handle. A wheel finds a seam. The cart lurches. A stack of brushes in a crate tilts like a small forest deciding to migrate.
Iruka does not shout. "Hands," he says.
Izayoi's palms are already up. A brush escapes and rotates end over end, bristles first. He does not snatch. He lets the brush meet his left hand where his left hand already planned to exist. The brush sits in his palm like it chose him. He returns it to the crate with the bland efficiency of inventory.
The chunin mutters thanks that sounds like apology. Iruka inclines his head the way you greet competence in other people without making them think about it too long.
"Water alcove," Iruka says. "Stop at the line."
They stop at the alcove where a basin sits and a posted list repeats rules nobody ever reads until they have broken them. Iruka folds his arms. Hinata blinks confusion into control and releases her eyes. The veins step back under skin.
"Byakugan off," Iruka says, though she has already done it. "Water. Then the return."
Naruto tries to be helpful and gets the cup stack stuck for a second. Shikadai frees it without ceremony and hands him one. Naruto hands it to Hinata with both palms like humility borrowed from a festival.
"Thank you," she says.
"Ribs paid," Iruka says quietly, and Naruto looks down at his own chest as if to check whether he owes.
Mizuki steps closer enough to be counted. He keeps to the wall like it is a friend. "For the file," he says, and the clipboard knows when to be a prop. "Byakugan use under supervision logged. Drill observed. No collisions. One assist on stairs. Excellent." He glances at Izayoi without making eye contact feel like a test. "Izayoi, a quick word - now or in office. Your choice."
Iruka does not make them guess. "Answer now," he says, tone neutral. "We will return after."
Mizuki's smile is administrative kindness. "Simple question," he says. "In front of your instructor, so there is no weight to it. When you performed substitution by the window, did you feel any pressure behind the eyes or in the temples. Yes or no. If yes, degree."
"No," Izayoi says. He lets the answer carry itself and stops there. If Mizuki wanted more, he would have asked.
Mizuki notes something in a neat hand that does not race to keep up with itself. "Second - phrased carefully. When you perform without seals, do you rely on any external crutch such as a mantra, object, or breathing trick beyond standard Academy teaching."
Iruka's face is furniture. Hinata sips water and looks at the basin iron because eye contact is labor.
"I practice control," Izayoi says. The sentence arrives familiar because it is the same truth he keeps giving. "I decide the after first. I place breath where the movement will end."
Mizuki writes three words and a small dot. He looks up, smile unchanged. "Thank you. It matters that we write what is true and only what is true."
Iruka takes that as the end of the conversation. "Return route," he says to the class. "Same rules on the way back. Hinata - you may stay deactivated unless I ask otherwise. Palms visible. Ankles honest. From the alcove to the classroom door, ribs only."
Naruto groans like ribs owe tax. Shikadai says nothing and pays with attention.
They move. The corridor is the same corridor and not the same corridor because return has different weather than departure. A water drop from the basin chooses the floor and fails to become a problem. A girl with a broom obeys her own idea of rhythm and does not hit anyone. The window light has shifted by a degree and writes its rectangles in a slightly different grammar.
Izayoi takes it all and refuses to be interesting. Interesting is for parties and reports. Corridors ask for uninteresting excellence.
"Quiet," Hinata says of her own accord, eyes normal now, and she sounds relieved that quiet is what the corridor has decided to be.
They reach the bend. The rail gets a touch from Izayoi's knuckles because rituals are how you make the world behave when you cannot own it. The landing is clear for ten heartbeats and then a flurry of papers tries again.
The first-year has learned. He puts his back to the wall and catches with his chest, not his reach. He nods at Izayoi because gratitude likes practice. Izayoi nods back because humility is also a drill.
"Classroom door," Iruka says, once the last rectangle of light lies where the floor wants it to.
They are almost at the threshold when Mizuki's clipboard taps against its own edge, the sound of process asking polite questions. "One more thing for the file," he says. "Iruka, your discretion. Afternoon session - I would like a brief repeat of rail constraint with Byakugan inactive, then active for exactly seven minutes. I will observe from the far window."
"Approved," Iruka says. There is no drama in the word.
Mizuki turns the smallest measure toward Izayoi. "In that session, the question will be whether silent movement stays silent when watched. That is not about you. It is about our rules. Understood."
"Understood," Izayoi says.
Iruka slides the classroom door with two fingers and lets the room hear itself again. Desks recover their shape. Chalk will be chalk. The basin water will dry without anyone missing a thing.
"Before we sit," Iruka says, holding the group in the doorway with tone alone. "Pairs will write three lines each - one about ankles, one about shoulders, one about centers. No seals named. Then we will go again."
Naruto inhales like a promise to behave for at least the first line. Hinata exhales like a promise to remember.
Mizuki remains at the corridor edge with his clipboard, present without being in the way. "Izayoi," he says, and stops because he already said the thing he came to say. He tilts the board against his chest like a shield that isn't one. "Good work."
Iruka raises his hand to start the next piece of the day.
"Izayoi," he says. "At the count. Palms up. We go through the room the way we went through the corridor. On three."
He lifts one finger.
Two.
Three.