"Begin," Iruka says.
Chalk hooks both their heels; the circle is a promise and a trap. Hinata stands square to him, hands half raised, shoulders drawn like a quiet breath.
"Words first," Iruka adds. "You may not move your feet. Ankles stay where they are. Small changes only."
"Tiger," Izayoi says, palms visible.
Hinata glances at his hands and echoes, barely louder than paper. "Tiger."
"Boar," he says.
"Boar," she repeats, and her inhale lands smooth instead of audible.
"Ox," he finishes.
The world doesn't swing; he edits the hinge. His torso takes the half-inch that legs would waste, the ribs moving first, shoulder a suggestion and not a destination. Hinata's reaching fingers close on air that used to be Izayoi's sleeve and finds only a whisper of cloth. Her feet do not budget; the chalk approves.
Iruka's voice is a ruler laid gently across the air. "Again. Narrate what you are doing, Hinata."
Hinata swallows, nods once. "Breath before," she manages. "Hands quiet. Elbow follows—" She doesn't say you; she says nothing at the end, and lets the sentence close politely.
"Better," Iruka says, not to praise but to keep the floor sturdy. "Tag his shoulder. No collisions."
Hinata sets her palm forward. Izayoi lets his balance tip the width of a grain and finds the new center before the old one goes missing. He keeps his palms up where Iruka can see them. Hinata's hand floats through the place he isn't.
Naruto's laugh bangs into the scene from the rear mat: "Ow—sorry! I'm okay!" Shikadai grunts that he warned him. Iruka doesn't turn; rooms learn what matters by watching what instructors bother to look at.
"Again," Iruka says. "Slow. Words first."
Izayoi: "Tiger."
Hinata: "Tiger."
"Boar."
"Boar." Her breath lands where she told it to; the exhale doesn't apologize for existing.
"Ox."
She reaches. Izayoi meets the contact he's been asked to deny by allowing the gentle version of it: her fingers graze the fabric over his deltoid and land with the softness of a thought you're allowed to keep.
"Thank you," she says, a reflex trained somewhere kind.
"You're welcome," he says. The right words dull edges.
Iruka steps closer, enough to count their blinks. "Constraint two," he says. He drops to a knee and draws a thin chalk bridge between their shoes—ankle to ankle, an inch of white connecting them like a law. "If this line breaks, you pay with five. Keep your seals spoken. Hinata, you lead. Izayoi, you accept."
Hinata's eyes touch the bridge and jump back as if looking too long might count as stepping on it. "Yes," she says, and the word is small but unbroken.
Iruka lifts his hand. "One."
"Tiger," Hinata says, a fraction stronger.
"Two."
"Boar." Her shoulders let go of a habit they never needed.
"Three."
"Ox," she finishes—and steps nowhere. Her arm extends with the purity of a lever; Izayoi turns a breath, then half of that, deciding to be touched where it costs nothing. Her palm lands with the idea of victory rather than the sound of it.
Iruka's mouth approves in the way that looks like no change at all. "Now reverse. Izayoi, you tag without moving your feet. Hinata, you accept what we call contact."
Izayoi nods. "Tiger."
Hinata: "Tiger."
"Boar," he says, already writing the path his shoulder will take. "Ox." He brings his hand forward with a care that reads as permission before it reads as pressure and rests fingers for exactly half a count on the sleeve of her uniform, a touch that puts nothing on her to carry.
Her eyes widen by a millimeter. Not fear—measurement. She bows her head a degree. "Understood," she says in a voice that finds its own floorboards.
The chalk line remains whole. Iruka taps it once with the back of his knuckle. "Good. You're learning to be small. People forget that small is where fights live." He straightens, attention scanning the wider room. "Naruto—stop throwing your shoulders at problems. Shikadai—don't enjoy being right so loudly. Everyone—hands visible or you pay."
"Yessir!" from the back, in two incompatible moods.
Iruka returns to the circle. "Constraint three," he says. "Call-and-response cadence. I say the number. Hinata, you say the seal. Izayoi, you move on the last syllable. Ankles do not migrate." He waits just long enough to see if anyone will confess to misunderstanding. No one does. "Ready."
"One."
"Ti—ger," Hinata says, the syllables clean as two small stones.
Izayoi doesn't move; the rule says move on the last syllable, and rules make your timing inexpensive.
"Two."
"Boar." The word is one step; he takes his half-inch shoulder edit after the -ar, catching the room on the right side of the sound. Hinata adjusts reception, not demand.
"Three."
"Ox." He turns the path into a hinge instead of a door; her hand lands with the intention, not the insistence.
Iruka lifts a knuckle. The chalk bridge is still a line, not a scatter. He seems satisfied but not impressed, which is the perfect teaching face. "Naruto, count out loud," he says without looking back. "Loud is allowed when it belongs to the room. Not your thoughts."
"Sir!" Naruto says, which is how some people say thank you for boundaries.
Iruka folds his arms. "Constraint four," he says, eyes on Izayoi. "Narration split. Hinata narrates both parts. Izayoi moves only on her words. No improvisation. If she fails to narrate a thing, that thing does not happen."
Hinata's breath hitches once and then decides to be steady. "Yes," she says.
Iruka waits. Teaching is choosing your silences.
Hinata swallows. "Tiger," she says, and the first word lays a small road.
"Boar," she adds, and Izayoi takes the hint—not the motion. He lets his shoulder telegraph the half-inch after the syllable leaves her mouth. "Ox." Her hand goes where a shoulder would be if shoulders didn't learn to file themselves thinner.
"Again," Iruka says. "This time with Naruto's noise as weather."
The back mat obliges: "ONE—Tiger! TWO—Boar! THREE—Ox!" Shikadai adds, "You don't have to yell like we're across a river," and Naruto, encouraged, yells, "WHAT?" which earns him five he pays quickly.
Hinata keeps the narration unshaken. "Tiger," she says. "Boar. Ox." The touch lands as instruction, not as proof.
Izayoi thinks, Good. Out loud he says nothing at all.
Iruka is not done. "Constraint five," he says, and he almost smiles for the first time today. It changes nothing and everything. "Eyes closed. Izayoi only. Hands visible. Hinata narrates. Ankles on chalk. I will test your balance with a very small tap on a shoulder when I choose. If you flinch your feet, you pay."
He doesn't ask if Izayoi understands. Understanding is what the exercise is for.
Izayoi lifts his palms where everyone can see them. He closes his eyes. He does not search the dark; he lets it sit where it is and counts himself down to quiet.
Hinata's voice is a string he can hold. "Tiger," she says, and he answers with nothing that the floor could hear.
"Boar." He lines his breath up with the edges of her word and lets his weight settle where the word leaves it to live.
"Ox." He takes the invisible hinge and turns it.
Iruka's knuckle touches Izayoi's right shoulder with a pressure too small to deserve the name. Izayoi's weight acknowledges the suggestion without moving to obey it. The chalk listens beneath his heels and stays a line.
"Again," Iruka says. "No seals this time. Hinata—no words. Ankles home. Begin on my count."
She glances at Izayoi's face with the quick fear you keep in a box and only open when no one can see. She closes the box. She nods.
"One," Iruka says.
Izayoi does not open his eyes. He lets the room be a map of pressures instead of shapes.
"Two."
He meets the thought of a hand the way a patient person meets a knock: by deciding the door first.
"Three," Iruka says.
"Begin."
Izayoi shuts his eyes tighter by exactly nothing. He chooses in the dark whether he will be a door or a wall.