Shin stared at the ceiling.
The dim glow of his phone screen had faded, and the room was quiet again—just the hum of the AC and the gentle rhythm of Ai's breathing as she lay curled against him, head on his shoulder, arm loosely around his waist.
She'd fallen asleep fast.
Or so he thought.
He shifted slightly, careful not to wake her, still riding the nervous buzz of having sent that last message to Yuki. His chest rose and fell in a quiet rhythm, but his mind was anything but calm.
Then he felt it.
Fingertips brushing along his jaw, gentle and slow.
"…You're not sleeping?" he muttered, glancing down.
Ai looked up at him with a sly grin, eyes wide open and sparkling in the darkness. "Nope."
"You little sneak."
"I wanted to see how long you'd lie there pretending to be brave."
Shin rolled his eyes. "I am brave."
"Mmhm," she teased, scooting herself halfway up his chest until their faces were close, the oversized T-shirt she wore—his shirt—sliding off one shoulder to reveal smooth skin. "But you were nervous. I could feel it in your heartbeat."
He blinked.
Ai softly pressed her hand over his chest like she was confirming it again. "Still fast."
"You're imagining things."
"I'm not," she said sweetly. Then giggled. "Yuki must really be something if he's got my fearless Onii-chan all shy."
"I'm not shy," he muttered again.
She smiled. "You are. And it's adorable."
She shifted again, her chest softly pressing against his side, her cheek brushing against his. "You know… I could help."
"…Help?"
Ai tilted her head, lips close to his ear, voice teasing. "If a little kiss on the cheek isn't enough… maybe a kiss on the lips would help calm you down, my hero."
Shin stiffened instantly. "Oi—!"
"I'm joking!" she laughed, flopping back beside him but still clinging. "Well, mostly."
"Brat."
"I'm serious though," she said, quieter now. "If it helps you feel better, I'll do anything. Because you're everything to me. You always have been."
Shin turned his head slightly. Her expression wasn't just teasing anymore—it was genuine. Adoring. It was the look she always gave him, like he was the entire world to her.
"You wear my shirt," he said flatly.
"Because it smells like you," she replied instantly, nuzzling her face into the collar. "And it's big and warm and soft. Just like you."
He groaned softly. "You're beyond clingy."
Ai smiled like it was a compliment. "I'm your number one fan, Onii-chan. Always have been. I don't care what anyone thinks. I love you more than anyone else. I worship you."
"Too much," he said, his cheeks tinged with embarrassment.
"Not enough," she whispered, pressing another kiss to his cheek. "You protect me, take care of me, and now… you're falling for someone. It makes me happy but also scared. Because I'll have to share you."
"…You're not losing me."
"You say that now," she murmured, voice soft. "But someday… someone else will take your heart."
Shin looked down at her.
Ai met his gaze, and for a brief second, her eyes shimmered.
Then, her grin returned. "But until that happens, I get to be your spoiled little sister. And I won't let any boy or girl make you nervous without giving you hugs first."
He chuckled. "You're impossible."
"I love you too, Onii-chan," she whispered—still holding onto him tightly like he might vanish if she let go.
Shin sighed, arms resting behind his head.
The weight of her against him wasn't heavy. It was comforting. Familiar.
Even with Ai pressed so close, he couldn't stop thinking about him—Yuki's shy eyes, those puffed cheeks, the way his lips curled when flustered.
Yuki was a boy.
Not a girl.
Not delicate in the way Ai was.
But somehow, Yuki made his heart race harder than anything else.
---
Ai's breathing was steady, but he could feel it—she wasn't asleep. Not yet.
She moved again. This time slower, deliberately rubbing her cheek along his shoulder, inhaling softly like she was breathing him in.
"You're really still awake, huh," Shin murmured, not even surprised.
Ai giggled, eyes still closed. "I like pretending. You get all thoughtful when you think I'm sleeping."
"You're such a pain."
"You love me."
"I do," he admitted without hesitation.
Ai's lashes fluttered open, and she looked up at him. "You mean it?"
Shin glanced at her and gave a soft smile. "Of course. You're my little sister. You've been with me since forever."
She beamed and cuddled closer, snuggling into his chest and letting out a dreamy sigh. "Just us two in this tiny place… You and me against the world."
"Yeah."
"I still remember when we first moved here. Just boxes and ramen cups… and you holding me while I cried like a baby because I missed Mom and Dad."
Shin's jaw clenched for a moment. "You were a kid."
"I'm still your baby," she whispered, fingers curling lightly in his shirt. "But I grew up too. And I realized… no one in this world loves me like you do. And no one makes me feel safer."
Shin exhaled quietly, fingers lightly brushing her hair. "You're not supposed to say stuff like that. You'll scare off your future boyfriend."
Ai scoffed and leaned up slightly to look him dead in the eyes. "As if I'd ever date someone else. No guy in this world is half as strong, kind, or cool as you, Shin. You're perfect. You're my ideal."
He stared at her for a long second.
"…Ai."
"What?" she pouted. "I'm being honest. I don't need anyone else."
Shin looked away, cheeks faintly pink. "You're just saying that because you're tired."
"I'm not tired. I'm obsessed."
"You're too much sometimes."
"And you're not enough sometimes," she huffed, then immediately softened. "That's why I hold you tighter."
She cuddled even closer, her breasts pressing softly against his arm now. Her legs were tangled with his, her whole body relaxed like she belonged there—like it was her place.
Ai rubbed her cheek against his bicep, then gave it a tiny kiss.
"…You really don't mind me being like this?" she asked suddenly, voice small. "Always clinging. Always needing you. I know it's a lot."
Shin was quiet.
Then he sighed and wrapped an arm around her.
"…No. I don't mind," he said, pulling her a little closer. "You've always been like this. You're my sister. I'll take care of you no matter what."
Ai smiled with teary eyes. "You're such a liar."
"Huh?"
"You say stuff like that, then go get all blushy and dumb over some pretty boy."
Shin blinked.
"Shin… can I tell you something for real this time?"
He looked down, brushing her bangs from her face. "Yeah?"
"I really, really love you."
He smiled. "I know, dummy. I love you too."
"No." She leaned back just enough to meet his eyes, her expression surprisingly serious, eyes big and shining in the soft room light. "I mean, like… love you."
Shin blinked, stunned silent.
"I know I'm your sister. And I know you like Yuki. And I totally support that," she rushed to add, resting her hand over his chest gently. "I just… I wanted you to know. Before I kept bottling it up and pretending."
"…Ai."
"You're my hero, Shin. You always have been. Ever since I was little, you made me feel like the safest place in the world was anywhere you were. You take care of me, you protect me, you always listen even when you're tired. You made this place feel like home."
She laid her head back on his shoulder, voice softening. "And somewhere along the way, I just started… feeling this way. Like, if I could choose anyone in the world to be with… I'd always pick you."
Shin's heart squeezed a little. Not from discomfort—but from how pure her words were. There wasn't a hint of darkness in her voice. No guilt. No twisted desire. Just a soft, warm truth she had kept hidden inside for so long.
"I'm sorry," she whispered. "I know I can't be your Yuki. I don't want to make you uncomfortable. I just… needed to tell you once."
He was quiet for a while. Then slowly wrapped his other arm around her and hugged her gently.
"You didn't make me uncomfortable," he said quietly. "You just caught me off guard."
Ai looked up, surprised.
"You're the most important girl in my life, Ai. That's never gonna change. And even if it's not the same kind of love… it's still real, okay?"
Ai nodded slowly, blinking tears away. "Okay."
Shin smiled softly and tapped her forehead. "Also, you're not allowed to cry, dummy. You're too cute for that."
She giggled and sniffled, cuddling back into him. "So I'm still your number one girl?"
"You've always been."
"I'll accept that," she whispered, nuzzling his chest.
She settled again, small and content against him, her fingers gently tracing over the fabric of his shirt as if memorizing the shape of him. Her tone lightened.
"Still," she said with a sly little smile, "You better not let that cute boy steal all of your attention."
Shin chuckled. "He already is."
Ai gasped playfully and pouted. "Unfair! I was here first!"
He smirked, then leaned his head back on the couch, eyes finally starting to feel heavy. "I'm not going anywhere, Ai."
"Promise?"
"Promise."
She squeezed him tighter, whispering, "Good. Because I'm not going anywhere either."
Her head was nestled under his chin, her small frame practically molded to his side in that clingy way she always did. Shin smiled to himself, a rare, soft curve of his lips.
"You know," he murmured into her hair, "my favorite thing about you…"
Ai blinked slowly, turning her face just enough to peek up at him with her wide, curious eyes. "Hmm? What is it?"
He looked down at her and brushed a strand of hair from her cheek, his voice gentler than usual. "The way you say 'Onii-chan.'"
She blinked again, surprised.
Shin chuckled a little. "I don't know how to explain it. It's just... when you say it with that sweet voice, like I'm your whole world… it makes something in me melt."
Ai's cheeks warmed up instantly, and her heart skipped a beat.
"I've been called a lot of things," he added with a small grin, "But when you say 'Onii-chan' like that, like it's the most natural, affectionate thing in the world—it feels like I matter. Like I'm good enough. Like I'm really… your hero."
Ai covered her mouth with her hand, bashfully hiding her expression—but her eyes sparkled.
"O-Onii-chan…" she said, softer than before, drawing out the syllables just a little.
Shin exhaled slowly, feeling his heart tighten in the best way.
"Yeah… that," he whispered. "That's the one."
Ai giggled softly, then reached up and kissed his cheek in return, her small hands cradling his face with so much gentle love. "Then I'll say it forever… Onii-chan."
He closed his eyes for a second, just holding her. No one else in the world ever made him feel like this—so needed, so seen, so loved in this impossibly innocent way.
"You're dangerous, you know that?" he muttered with a smirk, nuzzling her hair.
Ai smiled sleepily. "Only for you, Onii-chan…"
---
Ai's eyes fluttered open again when Shin shifted under her, his heartbeat still slightly fast beneath her ear.
"Still nervous, Onii-chan?" she whispered, voice soft and dreamy like a lullaby. Her arms tightened gently around his neck as she leaned up, brushing her cheek against his. "Want another kiss to feel better? I can try the lip one this time. Just say the word…"
Shin let out a quiet chuckle, low and amused. "You really don't hold back, do you?"
Ai beamed, unfazed. "Of course not. I love you the most in the whole world."
She said it so easily, like a truth that needed no justification.
Shin tilted his head slightly and flicked her forehead with two fingers. "You brat. You're gonna give someone the wrong idea with lines like that."
Ai just giggled, unbothered. "Let them. No one deserves my Onii-chan anyway." She squished her face against his chest, sighing dramatically. "If I had been born a little older, maybe I could've married you."
"That's not how it works, dummy."
She grinned. "Then I'll just stay like this forever. Your sweet little sister who never lets go."
He snorted, nudging his chin against the top of her head. "I don't remember agreeing to that contract."
"You don't need to. It's a lifetime deal."
Her words made Shin smile despite himself. Even with her ridiculous clinginess and dramatic declarations, there was something undeniably comforting about her presence. She was soft in all the ways the world wasn't—warm, sincere, endlessly loyal. No matter how badly a day went, Ai was always waiting with a hug, a snuggle, and an absurd compliment.
"You really worship me too much," he murmured.
Ai looked up, eyes wide and honest. "I do."
He raised an eyebrow. "That's not normal, you know."
"I don't want to be normal." She sat up just slightly, her thighs still loosely draped across his lap, fingers brushing his cheek again. "I just want to be yours."
Shin stared at her for a long second, then smiled. He placed a hand on the back of her head and leaned forward just enough to brush a kiss on her forehead. Then her cheek. Then another, slower one on the tip of her nose.
Each one made Ai go a little softer in his arms.
"Then this is your reward for being weird," he whispered.
Ai gasped and giggled, breath catching when he kissed the corner of her mouth—not on the lips, but close enough to make her blush explode.
"Shin!" she squeaked, burying her face in his shirt. "You—you said you wouldn't—!"
"I didn't," he said smugly, resting his chin on her head again. "But I could've. If I wanted to."
"You tease…"
"I learned from the best." He poked her side lightly. "Didn't you offer first?"
"I was joking!"
He smirked. "Were you?"
Ai made a tiny distressed noise and curled tighter into him. "You're evil sometimes…"
"And you're a menace. I think it runs in the family."
They stayed quiet for a bit after that, wrapped up in each other, her breath soft and warm against his collarbone.
---
END OF CHAPTER : 7 : CLINGY SISTER!
---