The late summer air carried a sweetness like overripe fruit, and the river moved slow and heavy beneath a sky the color of pewter. Itsuki and Haruto had spent the day at their usual place, skimming stones and pretending the river was an ocean that needed saving. They had chased crickets between reeds, stolen an apple from a careless vendor, and argued—briefly—about whether a dragonfly could outrun a sparrow. Laughter had stitched the afternoon together, until the light thinned and the world took on its softer, uncertain edges.
Itsuki wanted to linger. Haruto, as always, wanted to go on one last adventure. "One more race," Haruto insisted, grinning with that fearless tilt to his chin. "To the old willow and back. Loser gets splashed." Itsuki's small chest fluttered at the thought, but he agreed. Running with Haruto was a lesson in trusting your feet, and it had become easier to trust lately.
They slipped through the reeds, racing across wet stones, breath sharp in their throats. Itsuki's legs ached pleasantly; he could feel the river's coolness on his ankles and the thrill of the chase like a small sun rising in his belly. Haruto surged ahead, then turned, already laughing. Itsuki pushed himself, teeth clenched, the world narrowing to the slap of his feet and the sound of Haruto's voice.
Then something changed.
A sound, low and wrong, threaded through the air—like a cord pulled tight. The birds fell silent. Haruto stopped mid-step, head cocked, and for a second the two boys only watched the river. From the line of trees beyond the willow there came a movement: a figure, not quite right, sliding into the open like shadow that had learned to walk.
Itsuki's small heart stuttered. He had heard the old people speak of demons—stories told to keep children from wandering at dusk—but those were tales for fireside mouths. This was a presence that bent the air, an absence of warmth that pressed against the skin. The figure moved with terrible, practiced grace. When it turned, Itsuki saw the face the old stories had never prepared him for: cold, precise eyes and a smile that did not reach them. He had a name the village whispered and spat—Kaigaku.
Haruto took a step forward, the same fearless impulse that had charmed Itsuki so many times before. "Who are you?" he called, voice small and brave. It was a question only a child could ask a monster and expect an answer.
Kaigaku's head tilted, amused, and the space between them folded like thin paper. What followed was quick—terrifyingly quick—so fast that Itsuki's mind could not stitch the sequence properly: a flash of movement, the scrape of fabric, Haruto's breath cut short. It was done with an economy of cruelty, a single merciless motion that left Haruto crumpled on the bank.
Itsuki's world narrowed to two sounds: the river's unbothered murmur and the small, stunned sound that escaped his own throat. For a staggered moment he believed Haruto would rise and grin, brush himself off, insist this was a trick. But Haruto did not move. The laugh that had always come to the surface of him was gone. Where Haruto had been bright and alive, there was now a terrible stillness.
Kaigaku stepped back, as if inspecting a painting he'd finished, and a look that might have been pity—if monsters were capable of pity—passed over his face. "Foolish little thing," he said, voice silk over steel. "You cling to your small courage." Then, with the same measured detachment, he turned and faded back toward the tree line, like a shadow slipping into night.
Itsuki stumbled forward, fingers finding Haruto's sleeve, clutching with a strength he didn't know he had. The fabric was damp and warm from the river; Haruto's small hand lay limp and too light in his grip. Itsuki pressed his face to Haruto's shoulder, and the sound that rose from him was not a child's cry alone. It was a sound threaded with bewilderment, with the raw edge of disbelief, and beneath it—clear and terrible—an ember of something else: hatred.
When the village came—adults, voices sharp, lanterns bobbing—Kaigaku was gone. Itsuki watched them lift Haruto, carry him away, the night swallowing the shape of himself like an animal backing into a hollow. Arguing voices circled: someone swore they had seen movement in the trees; someone else whispered about demons and the need to alert the slayers. Itsuki heard the words but they floated, distant and useless. The world, he felt with a cold new precision, had a cruelty that could reach across the willow and take what it pleased.
That night, wrapped in a blanket that smelled like smoke and grief, Itsuki could not sleep. The stars outside were indifferent pins of light. He pressed his hand to his chest where his small ribs rose and fell, feeling the rhythm that had once been only comfort. Now it felt like a call. His mind replayed Haruto's grin, the way the boy had leaned his head on Itsuki's shoulder that morning and told him, "We'll always have adventures." The memory became a blade in his chest—sharp, warm, and impossible to ignore.
Hatred, Itsuki realized, was not a single bright thing. It was a slow kindling—small, almost domestic at first—then gathering like smoke until it filled the room. It was not the kind of emotion a child should hold, but it came anyway, heavy and exact: hatred for the thing that had taken Haruto, for the shape of its violence, for the helplessness that had hollowed him out.
By dawn, his resolve had hardened into something that would not be soothed by time. The river still flowed. The willow still bent its branches. But where laughter had once lived, there was now a small, steady promise in Itsuki's chest: he would learn. He would remember. He would not let that moment exist as only a wound. It would be the beginning of something—harsh, shaping, and inevitable. The world had taken warmth from him, and he would answer in the only way he could imagine: with a long memory and a growing will to stand against the shadows that took without asking.