Six months into Kairi's life, she had developed two reliable skills.
The first was sleeping through almost anything—Hiroshi's sword drills in the next room, the neighbor's dog barking at shadows, or rain hammering the windows hard enough to sound like applause. She could sleep through all of it without stirring, tucked into her cradle with her fists pressed against her cheeks, entirely unbothered by a world that was still mostly noise to her.
The second skill was waking up the fractional second Riku lost his concentration.
He didn't understand it at first. Babies woke up randomly; that was simply the biological reality of an infant. He had no reliable frame of reference for sleep patterns from his previous life and no particular reason to assume there was a pattern here beyond coincidence and bad timing.
Then he started tracking the data.
Fourteen times in three weeks. Every single instance where his focus had slipped during training—a surge of frustration at a form that wouldn't cooperate no matter how many times he repeated it, a moment of impatience that frayed the edge of a mana channel he'd been trying to hold steady, or one particularly bad afternoon where he'd pushed harder than his reserves could sustain and sent energy scattering across the room—Kairi had woken up. Sometimes it was just a soft, confused whimper. Sometimes it was a full-volume announcement that something was wrong and she needed everyone in the house to be immediately aware.
He began timing the gap between his mental lapse and her response. The average was four seconds.
He mentioned it to Yuki on a Tuesday morning while Kairi slept nearby, the 1988 morning light falling across the cradle in pale, dusty stripes through the window. Yuki was sketching diagrams for his next lesson, her brush moving in the small, precise strokes she used when she was thinking through a problem at the same time as doing something else.
"I know," she said, without looking up from the parchment. "I've been watching the correlation too."
"What is it?"
She set her brush down and turned to face him fully—the gesture she used when a topic deserved his complete attention. "The thread between you. It conducts more than warmth, Riku. When your energy becomes unstable—frustrated, rushed, or pushed past what your control can currently handle—she feels the displacement. Not the emotion itself, exactly. More like the interference that comes with it. The static."
Riku looked at the cradle. Kairi's chest rose and fell in the slow, deep rhythm of genuine sleep. One fist pressed against her cheek, entirely unbothered.
"So when I lose control—"
"She does too," Yuki said. "In the only way she currently knows how. She can't process the feedback she's receiving through the connection, so it manifests as distress." She paused, her eyes softening slightly. "She'll grow into it. She'll learn to filter what comes through the noise. But right now, your discipline is also hers, whether you intend it to be or not."
As if to underscore the point, a clinical notification appeared at the edge of his awareness.
[QUEST UPDATED]
Soul Thread — Maintain the connection
New condition detected: Thread stability affected by User's emotional state. Maintain internal equilibrium to ensure connection quality.
He dismissed the screen without showing any outward reaction, but he sat with what Yuki had told him for a long moment.
In his first life, he'd been accountable only to himself, and somewhere along the way, he had quietly turned that independence into permission for carelessness. Small failures he told himself didn't matter because no one else was affected. Hours wasted. Projects abandoned the moment they got difficult. It was the slow accumulation of almost-tried and nearly-started that had defined twenty-nine years he couldn't get back.
He looked at his sister sleeping in the morning light.
He didn't have that excuse anymore.
--DxD--
That afternoon, Yuki cleared the central training space and set a single target at the far end—a small wooden disc on a low stand, plain and familiar. Riku had been hitting it accurately for two months. It was the kind of exercise that had stopped requiring thought, which meant it had stopped producing growth.
He'd been wondering when she would change it.
"Basic mana pulse," she said, taking her position to the side. "Controlled release, clean recall. You know the mechanics."
He nodded and settled into his stance. He pulled up his skills screen briefly, checking his current Mana Control level out of habit before beginning.
[SKILLS — MAGIC TREE]
Mana Control Lv3 (XP: 15/100)
Mana Awareness Lv2 (XP: 67/100)
Formula Visualization — LOCKED
(Requires Mana Control Lv5 and a breakthrough condition.)
He closed the screen. Mana Control Lv3 was where it had been sitting for three weeks without moving. The mechanics were sound—he could feel the technique well enough. What it needed was a fluidity he couldn't simply force.
He found his center the way Yuki had taught him—not forcing the calm, just returning to it like walking back into a room he'd briefly left. Mana pooled in his palms with the steady, measured weight of something practiced into habit. The target sat at the end of the room, patient and still.
He sent the pulse.
Yuki moved the target.
Not far—barely six inches to the left, quick and smooth, a motion she'd clearly planned and timed carefully. But Riku had already committed. The pulse was traveling before his eyes had registered the shift, and the calculation that had been correct a half-second ago was now a failure, and there was nothing to do about that except watch it happen.
The pulse hit empty air. With no target to anchor it, the energy had nowhere to go and scattered, rippling outward in an uneven wave of blue-white light that wasn't dangerous, but wasn't controlled either—dispersing across the room in every direction at once.
[SKILL CHECK FAILED]
Mana Control Lv3 — Pulse dispersal detected.
Cause: Commitment timing. Control window too narrow for target deviation.
Correction: Hold commitment by 0.3-0.5 seconds. Maintain reserve control.
From the cradle in the corner came a sharp, startled cry.
Riku was moving before the sound had fully formed. He crossed the room in a few quick strides and looked down at Kairi. Her face had gone red with the effort of expressing her complete displeasure at being disturbed from perfectly good sleep for no reason she could identify. He reached in and offered his finger. She found it immediately, her grip closing around it with the iron certainty of someone who had decided this was the correct and appropriate response to the situation.
The crying didn't stop. But it dropped—from urgent to merely indignant, which with Kairi was a meaningful distinction.
He stood there and waited. Her grip tightened and released in an uneven rhythm, like she was working through something, processing whatever jagged vibration had come down the thread between them and disrupted her sleep. He could feel it from his end—a faint agitation, already beginning to settle as his own heart rate slowed and his energy steadied.
[QUEST UPDATED]
Soul Thread: Stability restored. Maintain control.
"I'm sorry," he said.
It felt strange, apologizing to someone who couldn't understand the vocabulary. But she was oriented toward him with her still-unfocused eyes, and the thread was carrying a truth between them that he couldn't fully name. She deserved the acknowledgment regardless of whether she could parse it yet. He said it for himself as much as for her—a small, deliberate act of accountability, making the failure real rather than something easy to dismiss.
The crying wound down into a series of hiccupping complaints and then, with one final expression of general dissatisfaction at the world, silence.
Her hand kept its grip on his finger.
Yuki hadn't moved from her position. When Riku finally looked up, his mother's expression was thoughtful in the way it got when she'd already reached her conclusion and was waiting to see if he'd reach the same one on his own.
"The pulse scattered," Riku said, his voice flat. "I'd already committed when you moved it."
"I know," Yuki said. "That was intentional."
"You moved it on purpose."
"Yes."
He looked back at Kairi. The system had been running clinically in the background through all of it—logging the failed calculation, flagging the dispersion pattern, already laying out the correction. He could fix the technique. That part was mechanical.
The other part wasn't mechanical at all.
"You wanted to see what my first instinct was," Riku said. "Whether I'd go straight to analyzing the technique or check on her first."
"Yes," Yuki said simply.
She crossed to the cradle. "You checked on her first," she continued, and her voice lost its instructional edge, softening into quiet approval. She looked at Kairi with an expression that had none of its usual precision. Just uncomplicated love, the kind that doesn't need to be explained. "That was correct. Technique can be corrected in the next repetition. Some things cannot."
Kairi yawned enormously, apparently satisfied that the universe had acknowledged her grievance and restored proper order, and let her eyes drift closed.
Yuki straightened. "Again. From the beginning. This time I'll move it twice."
Riku returned to his position.
He checked the skill notification the system had given him earlier: Hold commitment by 0.3-0.5 seconds. Maintain reserve control. Clean, precise, exactly the advice he needed. He breathed in slowly, found his center again, and felt the mana settle into his palms.
He also felt the thread—faint and constant, running from somewhere in his chest to the cradle in the corner. Kairi's presence at the other end, small and warm and trusting in the uncomplicated way she trusted everything about him, without requiring reasons.
Don't scatter, he thought. Not today.
He sent the pulse. He held his commitment back by half a beat this time, keeping a fraction of control in reserve, keeping the leash on the energy taut.
Yuki moved the target.
He caught it. The adjustment came late and cost him precision at the edges, the pulse arriving slightly ragged, but it reached the new position and recalled cleanly. Behind him, the cradle stayed quiet.
She moved it a second time.
Cleaner. The correction came faster, the adjustment almost natural, like a gear finally finding its slot rather than a movement having to be invented from scratch.
[SKILL CHECK PASSED]
Mana Control Lv3 — Mid-flight adjustment successful.
Adaptation noted. Control window expanding.
[SKILL PROGRESS]
Mana Control Lv3 — XP: 40/100 (+25 XP)
Observation Lv2 — XP: 55/100 (+18 XP)
"Better," Yuki said. Clean and simple. Just the accurate acknowledgment of a fact. "Again."
They ran the drill until the light through the windows had gone golden with late afternoon, Yuki varying the timing and direction without pattern or warning, forcing Riku to hold his commitment loose enough to respond to anything. He failed several more times. Each time the cradle stirred, each time he stopped, crossed the room, apologized quietly, and returned to position.
By the end, the failures were fewer and the corrections were instinctive.
[ACHIEVEMENT UNLOCKED]
Steady Hand
Control isn't the absence of distraction. It's choosing precision in spite of it.
Reward: +1 WIS, +1 DEX, 75 XP
[SKILL PROGRESS]
Mana Control Lv3 — XP: 78/100
Level up approaching.
He noted it without reacting. Mana Control Lv4 was close. Not today, but close. He filed it away and began helping Yuki clear the training space, stacking the target stands against the wall with the methodical efficiency she'd drilled into him from the beginning. Training ends completely, or it doesn't end.
--DxD--
That evening, after dinner, Riku sat on the back step of the manor while Yuki put Kairi to bed inside. The garden was dark, the 1988 sky thick with a cloud cover that had swallowed the stars entirely. Beyond the garden wall, Kuoh produced the low, constant hum of the economic bubble—the distant sound of high-end engines on the arterial roads, the glow of the commercial districts reflecting off the underbelly of the clouds. Ordinary life going about its business over hidden things.
Hiroshi appeared and sat beside him without announcement, the two of them watching the darkness together in the easy silence that had become their habit after long training days.
"How did the magic session go?" Hiroshi asked eventually.
"I scattered the pulse," Riku said. "Woke Kairi up."
His father nodded slowly. "And then?"
"Fixed it. Mostly." A pause. "Mana Control is close to leveling."
Hiroshi nodded again, processing at his own pace the way he always did. "And the other thing."
It wasn't a question. Hiroshi had a way of knowing which part of a session mattered most without being told.
"I checked on her first," Riku said.
"Good," Hiroshi said. Just that. No expansion, no elaboration. The word landed with the particular weight his father gave to things he meant completely.
Another silence settled between them. Comfortable. The kind that didn't need filling.
"She's going to make training harder," Riku said eventually.
"Yes," Hiroshi agreed.
"And more important."
His father looked at him sideways—the look he used when something had surprised him and he was deciding how much to show. "Yes," he said again, with entirely different weight behind it than the first time.
Inside the house, faint and half-formed, Kairi made a small sound and then went quiet again. Riku tracked it through the thread—a flicker, there and gone, settling back into peace.
He pulled up his status screen one final time before calling it a night.
[STATUS]
Name: Riku Snow
Age: 5.5 years
Level: 7 (415/500 XP)
HP: 95/95
MP: 124/124
STA: 110/110
STR: 18 | DEX: 23 | CON: 17 | INT: 24 | WIS: 23
SP: 0/0 (Sealed — Level 25 required)
[TITLE EQUIPPED]
Big Brother — +2 WIS when Kairi is within range
[ACTIVE QUESTS]
Sharpen the Edge — Reach Level 10 (Current: Lv 7)
Soul Thread — Maintain the connection (Stable — strengthening)
Small numbers still. But bigger than yesterday. That was the only measurement that actually mattered.
He closed the screen and let out a slow breath, watching the dark garden.
The road to Level 25 was still long. The worlds beyond were still waiting. The thing sealed inside his chest was still silent and patient.
But right now his sister was asleep down the hall, his father was sitting beside him in the dark, and tomorrow Yuki would move the target again.
That was enough to keep going.