XH woke up before his alarm.
Not fully awake, not fully asleep either. Just stuck in that thin space where your body is tired but your mind refuses to stop replaying one moment like it's a scene that keeps looping in a drama episode.
Sunlight leaked through the curtains, pale and weak. The room smelled faintly like detergent and last night's instant noodles. His phone buzzed once, then again, notifications stacking without urgency.
He didn't check them yet.
Because the first thing his mind did was pull him back to Friday.
Not the whole night. Not the laughter. Not Ocean. Not the arcade.
Just the classroom at Campus 2, warm with sunlight, quiet after the noise had left.
Kitty's face. Her eyes. The way she didn't step away.
The kiss wasn't dramatic. That was the problem. It was small enough to pretend it didn't count, and real enough to change the air between them.
XH turned onto his side and stared at the wall.
He tried to form a sentence.
A simple one. A clean one.
"About Friday…"
But even in his head, it felt wrong. Too blunt. Too late. Too early.
He sat up slowly and rubbed his face, fingers dragging down his cheeks like he could wipe away the uncertainty.
On his desk, his notebooks were stacked neatly. Anatomy Atlas 20th edition leaned against his laptop like a judge waiting to be opened. Beside it, his Notion page was still on-screen from last night, the cursor blinking under a title he never filled in.
Week 2 Summary:
Blank.
He exhaled and stood, pulling on his hoodie, then hesitated, checking himself in the mirror.
Normal face. Normal eyes. Normal mouth.
But his chest still felt loud.
At Campus 2, the hallways were already filled with familiar sounds, shoes scraping, voices bouncing, the smell of coffee trailing behind people like perfume. A few students were laughing too loudly near the stairs. Someone complained about lab coats. Someone else complained about the temperature.
The world moved on effortlessly.
XH wished he could do that too.
He spotted the group near the usual corridor, TR leaning against the wall with the confidence of someone who didn't know shame. TZ Royal was beside him, relaxed, one earbud in, nodding to a beat only he could hear. JP stood with his laptop bag, already tapping his screen like he was loading his day. HS smiled softly at something PL said, while PL talked with his hands like his life depended on it.
NS was there too.
But NS stood slightly apart.
Not far. Just enough that the air between him and XH felt noticeable.
XH's stomach tightened.
TR spotted him and waved like a flag. "Yo. Our singer is alive."
XH rolled his eyes. "Don't start."
JP glanced up. "Lab today."
TZ grinned. "Osmosis day. Membrane drama."
PL laughed. "Why does science always sound like relationship problems?"
HS smiled, eyes warm. "Because it is."
NS didn't say anything. He looked at XH once, then away.
XH pretended not to notice, which was the worst kind of noticing.
They walked toward the lab building together, the group flowing like a small crowd. TR talked loudly about food. TZ teased PL about wasting coins at claw machines. JP muttered about how he was making flashcards for biochem whether he liked it or not.
XH listened. Nodded. Laughed when appropriate.
But he kept scanning.
Not for Kitty exactly.
Just… expecting her.
And then he saw her.
Kitty was walking ahead with a couple of classmates, hair tied loosely, her bag held close to her side. She looked the same as always, neat and composed, like her calm was something she practiced.
When she turned her head and saw the group, her eyes flickered, then landed on XH.
For half a second, she didn't smile.
Then she did, softly, like she was choosing to make the world easier.
"Morning," she said when they got close.
"Morning," XH replied.
His voice came out normal. He hated that it could.
TR immediately greeted her like nothing in life could ever be awkward. "Kitty. Lab day. Pray for us."
Kitty laughed quietly. "You'll survive."
"Barely," PL said dramatically.
Kitty's gaze returned to XH again, quick as a heartbeat. She looked like she wanted to say something, then decided not to.
XH felt the same decision happen inside him.
They entered the lab.
White benches. Metal stools. Bottles lined up like soldiers. The smell of disinfectant mixed with the faint sharpness of chemicals. Posters of cell membranes and transport mechanisms covered the walls, smiling diagrams pretending biology was simple.
At the front stood THKM.
He looked like a man carved out of discipline. Shirt perfectly pressed. Glasses low. Expression unreadable. He didn't smile when students filed in. He waited until the room settled, like he expected respect without asking for it.
Behind him moved Lola, the assistant teacher, carrying trays and checking equipment. Her presence was different. Softer. Warmer. She smiled easily at students, her eyes catching details quickly.
When she passed XH's table, she nodded as if she recognized him, then kept moving.
THKM's voice cut cleanly through the room.
"Today is osmosis and diffusion," he said. "This is not theoretical. This is foundational."
He wrote on the board:
High concentration → Low concentrationSemi-permeable membraneSelective permeability
He turned, marker still in hand. "Choose partners."
Chairs scraped. People shifted.
TR immediately grabbed TZ's shoulder. "We're together. We're chaos."
JP moved with efficiency and paired with HS, already dividing tasks before anyone asked.
PL hovered like a lost child until someone pulled him into a table.
NS didn't move quickly. He looked around once, then chose a table near the side, alone for a moment, then a classmate joined him.
XH stood still.
He felt Kitty's presence near him before he looked.
They both reached for the same tray of materials at the same time.
Their fingers nearly touched.
They froze.
"Sorry," Kitty said softly.
"No, it's okay," XH replied too fast.
Kitty's lips curved slightly. "We can pair."
XH nodded, swallowing. "Yeah. If you want."
Kitty held his gaze for a moment longer than usual.
Then she looked down at the tray. "Okay."
They moved to a bench near the middle, close enough to be seen but not in the spotlight.
Lola walked by and placed extra gloves near them. "Good. Pair up and label everything clearly," she said gently. "Labs punish messy thinking."
TR shouted from across the room, "My thinking is always messy."
Lola smiled without looking at him. "Then today you will suffer."
The class laughed.
THKM didn't.
He continued, voice steady. "Osmosis is the movement of water across a semi-permeable membrane. Diffusion is the movement of solute from high concentration to low concentration."
He tapped the board with the marker. "Thick density to thin density. High to low. The system seeks balance."
Kitty pulled on gloves carefully, snapping them at the wrist. XH did the same, slightly slower, his fingers clumsy for a second.
Kitty noticed and reached over, adjusting the edge of his glove lightly. "It's okay," she said, almost automatically.
Her touch was brief.
But it landed in him like a small spark.
They began measuring solutions, one more concentrated, one more diluted. Clear liquids that looked identical but weren't. Kitty labeled beakers neatly. XH wrote down values on the worksheet, handwriting controlled but slightly tense.
"You're good at labeling," XH said quietly.
Kitty glanced up. "You're good at writing fast without making it messy."
He almost laughed. "I rewrite later."
Kitty's eyes softened. "I know."
That "I know" felt like it held more than lab work, but she didn't push it further.
THKM moved between tables like a judge. He stopped near them and watched their setup without speaking for a moment.
XH's heart sped up.
Kitty didn't flinch. She kept her hands steady, placing the semi-permeable membrane carefully between compartments.
THKM nodded once. "Correct."
Then he walked away.
XH exhaled slowly, realizing he'd been holding his breath.
Kitty glanced at him. "You always do that."
"Do what?"
"Hold your breath when someone's watching."
XH's ears warmed. "You noticed."
Kitty smiled slightly, and for a second it was the same smile from Friday, small and close to her face, like she didn't want to share it with the room.
Lola returned and leaned down near their bench. "Make sure your membrane is properly seated," she said. "Otherwise your results will lie to you."
Kitty nodded. "Yes."
Lola's gaze flicked from Kitty to XH. Not suspicious. Just aware. "You two work well together," she said.
XH's chest tightened. "We're… trying."
Kitty's eyes dropped to the worksheet. "It's easy to work with him."
The way she said it was calm.
But XH heard the tenderness underneath anyway.
They watched the levels change slowly.
Drops moved. Gradients formed. Numbers shifted in small increments.
It was quiet work. Patient work. The kind that made you sit with your thoughts.
Across the room, XH caught NS looking their way once.
NS's face was controlled, neutral, but his eyes lingered too long.
Then he looked away.
XH's stomach sank.
Kitty didn't notice.
Or she did, and chose not to.
THKM returned to the front and wrote another term:
Blood-Brain Barrier
The room quieted, like everyone instinctively knew it mattered.
"The blood-brain barrier is selective," THKM said. "It protects the brain. It allows certain substances through and blocks others. Without selectivity, you have collapse."
He paused, letting the word hang.
"Protection has a cost," he added.
XH's pen froze.
Kitty's pen froze too.
They both pretended it didn't.
Kitty spoke quietly, almost to herself. "So not everything that wants to cross… can cross."
XH swallowed. "Yeah."
Kitty looked at him.
Her expression wasn't accusing. It wasn't sad. It was searching.
Like she wanted to know what he was letting through.
And what he was blocking.
The beaker levels stabilized.
Kitty leaned close to check the final reading. Her shoulder brushed his arm.
XH's breath caught.
She didn't move away.
"Equilibrium," Kitty said softly.
XH nodded. "Balance."
Kitty's eyes flickered. "Balance isn't always happiness."
XH stared at her.
That sentence felt too sharp to be just about osmosis.
He wanted to answer.
He wanted to say something real.
But his mind did what it always did when his heart got too loud.
It delayed.
"It's… safer," he said weakly.
Kitty's lips pressed together slightly. Not angry. Just… disappointed in a way she didn't show often.
Lola called out, "Time. Clean your stations."
The room filled with movement again. Gloves snapped off. Paper towels wiped benches. Bottles clinked. TR complained loudly about how science was trying to humble him. TZ laughed and said science should try harder.
JP was already packing, results recorded neatly, like the lab never touched his emotions.
Kitty washed her hands carefully. XH did the same, standing beside her in silence.
When they finished, Kitty dried her hands and looked at him.
She didn't smile this time.
But her voice was still gentle.
"You did well," she said.
"You too," XH replied.
There were a dozen other things sitting behind his teeth.
He didn't let any of them out.
They left the lab and the group formed again in the hallway like magnets snapping back into position.
TR talked about lunch. TZ talked about a match highlight he watched. PL said he was starving like he hadn't eaten in a year.
NS stayed quiet.
XH walked beside NS for a moment, trying to close the space that had opened earlier.
NS didn't move away, but he didn't lean in either.
"You good?" XH asked quietly.
NS's eyes flicked toward him. "Yeah."
The answer was too clean.
XH nodded anyway.
Kitty walked a step behind XH, not by accident. Her pace matched his, but she didn't close the distance.
It felt like a boundary.
Not a wall.
A membrane.
On the courtyard path, Lola crossed them with a stack of papers in her arms.
She smiled briefly at XH. "Good focus today," she said.
"Thank you," XH replied automatically.
Kitty's gaze flicked toward Lola, curious, then returned forward without comment.
TR yelled, "Miss Lola, tell THKM to give us mercy."
Lola laughed. "Mercy is not in the syllabus."
The group laughed again, and the day tried to pretend it was light.
But XH kept hearing THKM's words.
Protection has a cost.
He thought about how easily fluids moved from high concentration to low, from thick to thin, across membranes that were designed to allow it.
He thought about how the body chose what to let in.
What to block.
He wondered if he was doing the same thing.
Not to protect Kitty.
To protect himself.
As they entered the next building, Kitty finally spoke again, voice quiet so only XH could hear.
"Lab partners again next week?" she asked.
XH's heart jumped at the possibility, and sank at the simplicity of it.
He nodded. "If you want."
Kitty looked at him for a long second.
Then she smiled, small and polite, like she was putting something away carefully.
"Okay," she said.
And she walked ahead, rejoining the others.
XH watched her back disappear into the crowd and realized something with a cold clarity.
Nothing dramatic had happened today.
No fight. No confession. No scene.
Just a kiss that lived in silence.
Just a friendship that started to carry weight.
Just a barrier forming, thin but real.
And that was enough to change everything.
Not loudly.
But permanently.