The staff office smells like paper that has decided to live a long time. Desks in rows. Files in gray verticals. A window that makes the light polite before it lands. A kettle sits on a low burner and refuses to boil where anyone can hear it.
Two people wait. One wears a flak vest with ACADEMY stitched small on the shoulder and a smile that looks like it asks for your name so it can file it correctly. The other wears a medic band on his sleeve and the careful posture of someone who counts heartbeats for a living.
"Izayoi," the flak vest says. "I'm Mizuki. Assistant instructor." He doesn't offer a hand; he tilts his head instead, an invitation to belong to the room without touching it. "This is Kenta from the infirmary. We'll be quick."
Kenta nods. His eyes are steady and uninterested in anything that isn't data. "Standard early-proficiency assessment," he says. "Your homeroom teacher noted you performed clone and substitution without hand seals. We'd like to see that again—slow, hands visible, and with narration. Then a brief control measure. No more than ten minutes."
Izayoi steps to the marked square on the floor that every office seems to have—the place where people stand when rooms want to measure them. He places his hands palms-out at waist height. "Understood."
Mizuki gestures, easy and permissive. "Begin when ready."
"Tiger," Izayoi says, because words keep the room honest. "I decide the after first." He glances at the empty chair against the far wall and then away, naming nothing out loud. "Boar," he says, and thins chakra along his skin until it lies like water where it would have snagged. "Ox," and weight moves inside the step before the step exists.
The clone unfolds to his left as if the office had always expected it. He trades places with the air a meter to his right. The chair ticks and does not complain.
Mizuki's smile doesn't change. His eyes do—one long blink when most people would offer three short ones. "Again," he says, tone polite, appetite invisible.
Izayoi repeats. The clone is neat, then neater. The substitution is small, then smaller. His hands never leave the air between waist and chest. He narrates the verbs and leaves the nouns at home.
"Good," Kenta says. He rolls a cart the size of a bedside between them, the kind that belongs in a clinic and wanders anyway. He lifts a coil of jointed wood and wire, soft leather lining the inside. "Thread gauge," he says. "It wraps your wrist and reads squeeze and release. Not a strength test—timing. Follow my count. In on 'one,' out on 'two.' Twice. Then I'll tug, and you resist with the least energy that keeps the coil where it is. Understood?"
"Yes," Izayoi says. He offers his left wrist. The leather is cool; the wire hums faintly like a polite insect.
"One," Kenta says, and the gauge warms under Izayoi's skin. Izayoi breathes in and lets the smallest contraction happen as a wave from fingers to elbow. The needle on the faceplate moves a hair and stops where a sane number would like to live.
"Two." He releases with the same wave in reverse. The needle comes home without bouncing. Kenta watches the dial, not the boy. Scientists do not watch faces unless faces are instruments.
"Again," Kenta says. "One." The coil warms a degree. "Two." The needle obeys.
Kenta pinches the coil's end and tugs three millimeters. "Resist to here," he says, tapping a modest mark on the dial.
Izayoi answers with exactly the energy Kenta asked for and not one grain above. The mark holds. The coil stops humming.
"Fine," Kenta says. "Control present, no obvious tremor." He unbuckles the coil. "Grip."
Izayoi takes the simple bar the size of a broom handle. Kenta points to a line on another dial. "Keep it there," he says. "Not above, not below."
Izayoi keeps it there. He does not win. He does not lose. Numbers relax when they land where they live.
Mizuki leans a hip against a desk and keeps being friendly. "No hand seals in class," he says, conversational as a weather report. "That's unusual."
"Yes," Izayoi says. Let true things carry themselves.
"How long?" Mizuki asks.
"Since I could make a clone, sir."
"And substitution?"
"After the clone."
Mizuki's smile gets six grams heavier. "Ambidexterity?"
"I write right-handed," Izayoi says.
"Good," Mizuki says, as if the word could be a direction, too. He gestures to Kenta. "Eye?"
Kenta lifts a small penlight and a wooden tongue depressor as if eyes and tongues ever needed the same tool set to be persuaded. "Look straight ahead," he says to Izayoi. "Track left. Track right. Pupillary response."
Izayoi tracks. He lets the light do what it came to do and keeps his breath where it belongs.
Kenta lowers the light. "Any recent headaches? Pressure behind the eyes?"
"Only when I stand up too fast," Izayoi says. It earns him a small, neutral nod. The kind of nod that says we all stand up too fast sometimes.
Mizuki's tone stays friendly. His words become narrower. "Any family history of ocular techniques?" he asks, careful with the phrasing. "Hyuga training in the orphanage? Now and again a cousin teaches the basics, even without a crest."
"I grew up at the orphanage," Izayoi says. "I learned to read the room."
Kenta sets the penlight down. "Oculars often present later," he says to the air. "No need to test visual cortex today. If you have flashing lights, blurring, or an aura, report. Otherwise: water, salt, rest."
"Thank you," Izayoi says, and lets gratitude be the end of that path.
Mizuki taps a sheet with his knuckle. Paperwork waits under glass. "Two cautions for the file," he says, and the words are as gentle as the knuckles. "One: no handseal-less demonstrations except under instructor supervision. It makes peers copy badly. Two: if you teach anyone anything, tell Iruka first, or tell me." The smile returns to full brightness. "We like good habits."
"Yes, sir," Izayoi says.
Kenta wheels the cart a half step back and finds the kettle with his eyes. "Tea?" he asks, and it doesn't sound like a test. "Boiled ten minutes ago. It has decided to be warm."
"I'm due back," Izayoi says.
Mizuki puts the sheet on a stack where other sheets will learn its name. "You are," he says. "Thank you for the time."
Izayoi inclines his head to both. He leaves the marked square the way you leave a tatami—without making the mat feel used. The door gives a polite click when it closes behind him.
The corridor looks longer on the way back because knowledge makes distances honest. He walks the center of it, half a pace slower than his thoughts, and lines his breath up with his steps: one in, one out; one in, one out. People look for what you show. Show small.
At the classroom door he pauses just long enough to let the sound inside tell him its temperature. Chalk. Paper. A boy's whisper refusing to be quiet. He slides the door, steps in, bows a degree toward the front.
Iruka looks up. Relief is a rumor that barely touches his face. "Back," he says, and it isn't a question.
"Yes, sensei."
"Good. We're pairing," Iruka says, and he does not call the roll. He points. "Hinata with Izayoi. Center aisle. Chalk circle stays. Naruto with Shikadai, rear mat. Everyone else, match by desk."
Naruto throws Izayoi a look that wants to be a fist bump and turns into two thumbs instead. Hinata stands as if standing were a form of speech you practice before you say it aloud. She moves to the circle and stops with her toes on the line.
Iruka steps close enough to own the air in front of them. "Constraint," he says. "Substitution without moving your feet. Only above the ankle, only under the knee. Words first. Small changes. If you have to move, pay with five. Ready?"
Izayoi nods. Hinata's eyes flick to his hands and back.
Iruka lowers his hand. "Begin."
Izayoi chooses, inside the length of the word, whether he will be a door or a wall.