Kids, Oppa’s Here
Siren's new single album showcase day, morning. The private makeup shop in Cheongdam-dong was bustling from early morning.
“Director, what concept should we go with for Actor Seo Eun-seong today? Should we slick it back heavily with pomade like in the movie?”
At the shop owner's question, Oh Ji-yeon shook her head, arms crossed.
“No. Today, mix in a spoonful of trendy idol vibes instead of movie star Seo Eun-seong. This is our company's first official public event for its inaugural actor, and Siren's showcase, right? Please go with an idol feel.”
At Oh Ji-yeon's detailed order, the shop owner and staff's hands moved busily.
“Eun-seong-ssi, close your eyes.”
As the experts' hands worked their magic, the Seo Eun-seong in the mirror was transforming into a completely different person. Instead of the pomade style that swept his forehead back coolly, his bangs fell naturally forward. An idol-like 'comma hair' style that just barely covered his forehead? His sharp jawline remained, but the bangs gave off a fresh, boyish charm.
His outfit was perfect too. Instead of a stiff all-black suit, he wore a deeply V-necked white shirt topped with a stylish beige oversized jacket. Every glimpse of his firm chest muscles through the V-neck exuded lethal sexiness.
“Wow? Eun-seong-ssi, you look like a photoshoot just breathing?”
“The reporters' camera shutters are gonna break from overuse today!”
The shop staff surrounded Seo Eun-seong, clapping like seals. Seo Eun-seong scratched the back of his head, finding his reflection in the mirror too unfamiliar and embarrassing.
“Ji-yeon noona... I mean, Director. Isn't this too dressed up? The shirt feels a bit too open...”
“What are you talking about? It's perfect. With your face and physique right now, even a burlap sack would look designer. We put extra care into it today, so have some confidence.”
Oh Ji-yeon brushed a lint off Seo Eun-seong's shoulder with a satisfied smile.
This noona... she's really serious about managing, Seo Eun-seong thought, sticking out his tongue in admiration of her drive and sense.
And so, after enduring the Ice Witch's perfect doll play(?), Seo Eun-seong headed to the battlefield.
2 p.m., one hour before the showcase started. The waiting room was thick with suffocating tension.
“Haa... It's not like this is our first or second comeback, so why do I shake every time?”
Seo Ha-rin paced the waiting room, gnawing at her nails. Normally, the Siren members would turn the waiting room into a playground like energetic beagles, but not today. It was their first comeback stage in six months. And the success of this title track would determine Siren's future path.
“Ha-rin unnie... my mind just went blank.”
“Ah-hyun-ah, calm down. We've practiced so much.”
Even the usually composed Lee Ah-hyun stared holes through her script, her lips trembling.
“Smart maknae? You're MCing today, right? You know you have to do well?”
Choi Eun-jin massaged Lee Ah-hyun's shoulders to soothe her.
“Ugh, my legs feel like cramping.”
Kim Chae-yeon clutched her perfectly fine legs.
“I'm hungry...”
Even Gomin-ji, the queen of sprawling out, sat rigidly on the sofa, spacing out.
That was when it happened.
“Kids, oppa's here.”
Click.
The waiting room door opened, and Seo Eun-seong entered, hands full of large paper bags.
“Oppa!”
“Bear Doll!”
The Siren members' gazes snapped to Seo Eun-seong. But...
“.....”
“Huh? What's up? Were you about to change clothes?”
At Seo Eun-seong's puzzled question, the frozen little sisters(?) finally gaped open-mouthed.
“Oppa, you debuting as an idol today?”
“Insane? Bear Doll? What's with the V-neck?”
Seo Ha-rin and Choi Eun-jin rushed over, unable to hide their shock.
“Eun-seong oppa... that's too sexy...”
“Seo Eun-seong-ssi, we're minors, you know?”
Lee Ah-hyun (17) and Kim Chae-yeon (18) said one thing but stared piercingly at his chest.
“Eun-seong oppa, your chest is huge.”
As expected, Gomin-ji was bluntly quirky.
“Bear Doll, you switching to idol?”
“You could totally be an idol, Eun-seong oppa!”
Starting with Choi Eun-jin and Lee Ah-hyun, everyone fussed over his comma hair and styling.
“Ahem. Idol? Nah.”
Seo Eun-seong cleared his throat awkwardly, then set the paper bags on the table.
“Figured you all might be tense, so I grabbed some macarons and sweet drinks from a dessert cafe nearby. Recharge your sugar.”
He flashed his signature warm, motherly smile as he handed out the snacks.
“Today's got that forbidden vibe, huh, Bear Doll?”
Choi Eun-jin chuckled. He looked like an idol, but his actions were still the warm Bear Doll who made sure everyone ate well. That perfect, incongruous gap melted away the members' tension, including Choi Eun-jin's.
“As expected, only our oppa! I was about to collapse from low blood sugar.”
“Thank you, Eun-seong oppa. I'll power up with this.”
Seo Ha-rin and the members huddled together, munching macarons. With the sweet treats kicking in, the waiting room buzzed back to its usual lively chaos in no time.
“Don't be nervous—just do your usual. You're the undisputed top in Korea. Wait, second to Sherazade? Anyway, go tear up that stage.”
Seo Eun-seong encouraged his little sisters(?) sincerely. His warm support reignited confidence in the five girls' eyes.
“Of course! Who do you think we are? Siren!”
Seo Ha-rin, who had been biting her nails moments ago, clenched her fist.
Yes. Seo Eun-seong's mere appearance had cranked the Siren members' energy back to max.
“If you're that good, how about Eun-seong manages our girls?”
Kim Tae-ho, watching, made the suggestion. No matter how hard he tried to ease their nerves, it hadn't worked—yet Seo Eun-seong fixed it instantly.
“Tae-ho-ssi? Sorry, but Eun-seong's going to be the top actor feeding our company, okay?”
“Y-yes... Sorry, Director. Just throwing it out there...”
Oh Ji-yeon was an iron wall, while Kim Tae-ho deflated.
“Heh.”
Seo Eun-seong just found the whole scene amusing.
“Now, we'll premiere the music video for Siren's new single album title track, Mystery Boy!”
With the host's energetic cue, the showcase venue lights dimmed.
“Oh? Starting with the MV, huh?”
Seo Eun-seong sat in the back-row VIP seats with Oh Ji-yeon and Kim Tae-ho.
Soon, countless reporters' camera lenses pointed at the screen. With the intro, a pastel-toned, refreshing high-teen school backdrop unfolded. Then came the Siren members' fresh visuals. The cinematography was stunning, and the trendy house-style track hooked the ears perfectly.
And as verse one neared its end...
Screech.
The library door opened, and a boy from the next class walked in holding a book. That was when it happened. Seo Eun-seong's face—in school uniform, eyes melancholic—filled the massive screen in close-up.
“Huh? That's Seo Eun-seong, right?!”
“It's Eun-seong oppa!”
Fans shrieked from spots in the dark audience.
“Seo Eun-seong was the MV lead?!”
“Yeah, it's him!”
Even the press section erupted in gasps. No entertainment reporter had anticipated Seo Eun-seong's surprise appearance. And he wasn't just an extra—he was the male lead, dominating the narrative with overwhelming visuals.
Then, the long-awaited highlight. Peeking through library bookshelves, Seo Ha-rin and Seo Eun-seong locked eyes. Her wistful crush gaze clashed intensely with his killer stare on screen. It was that 'business siblings acting' scene where they'd nearly barfed from how gross it felt.
“Kyaaah!”
“What?! What?!”
The invited fan section went wild.
“Their chemistry tho!”
“Siblings? I just got butterflies and now I feel guilty!”
“Face genes on point? Insane inheritance?”
The fans' reactions exploded. Even knowing they were real siblings, they couldn't stop over-immersing in the visual chemistry.
But the shocks didn't end there. The MV's latter half approached. At the end of Seo Ha-rin's longing gaze, Seo Eun-seong appeared secretly dating a young student teacher. The moment that teacher's face revealed...
“Whoa? Kim Na-yeon?!”
“Why is Kim Na-yeon there?!”
The showcase venue flipped upside down. It was the reunion of legendary bodyguard #1 from the movie Glorious Outing, who stole the screen, and top actress Kim Na-yeon. Their cameos alone blasted the MV's buzz through the roof.
After the music video screening, Siren's live stage followed. They nailed it flawlessly, leading into Q&A and talk time with reporters.
“The MV reactions are already explosive here on-site! Especially our MV's male lead this time—he's super special, right? I hear he's here cheering us on today! Actor Seo Eun-seong! Could we bring you up on stage for a bit?”
Lee Ah-hyun, handling part two MC duties, smoothly shifted to the MV topic. She didn't forget to wink subtly at VIP-seat Seo Eun-seong.
“Me? M-me?”
Seo Eun-seong startled, glancing at Oh Ji-yeon. This wasn't in the plan.
“Go up, say hi, and come back. Eun-seong-ah.”
Oh Ji-yeon didn't blink, even pushing his back.
“Haa... shouldn't have come.”
Seo Eun-seong reluctantly stood and walked toward the stage.
Just you wait.
Flash! Flash! Camera flashes burst with every step.
“Yes. Hello, it's Seo Eun-seong.”
He climbed onstage, lining up with Siren members, subtly eyeing Seo Ha-rin and the others.
And then...
“So handsome!”
“Eun-seong oppa! You're a total hottie!”
Woooah! The showcase heat surpassed any idol concert.
“Wow? You're really popular, huh? Good call bringing you up. Actor Seo Eun-seong-ssi.”
“Haha, you think? Ah-hyun-ssi?”
Seo Eun-seong was dumbfounded by Lee Ah-hyun's boldness.
“Please greet us.”
“Ah... yes. Hello. I'm Seo Eun-seong, Ha-rin's oppa who played the mysterious male student in the music video.”
He smiled shyly, making sure to mention he was Ha-rin's oppa.
“Kyaaah! So cool!”
“Ha-rin's oppa!”
The fans went nuts over 'Ha-rin's oppa' too. Of course—who else's girl group member had such a handsome real brother(?)? To Siren fans, Seo Eun-seong's existence was a huge point of pride.
“Actor Seo Eun-seong-ssi, your romance acting with Ha-rin unnie in the MV was the hot topic today. Must've been tough doing such tender scenes as real siblings... How was acting it?”
At Lee Ah-hyun's cheeky question, reporters' typing sped up.
“Hm.”
Seo Eun-seong glanced at his sister Seo Ha-rin mic in hand. She beat him to it, mischief in her eyes as she leaned in.
“Truth be told...”
Seo Ha-rin started seriously.
“When we shot the library eye-contact scene? The moment our eyes met, I felt so sick we almost stopped filming. Seeing oppa try to look all killer... I legit wanted to puke.”
“Hey? Seo Ha-rin?”
Seo Eun-seong bristled. Exposing behind-the-scenes like that?
“Kya! Hilarious!”
“Almost puked!”
Wahahaha! Fans and reporters burst into laughter at Seo Ha-rin's unfiltered real-sibling roast.
“Haa.”
Seo Eun-seong grabbed his mic, unwilling to lose.
“Since Ha-rin said that, I'll defend myself too. I was acting, so I tried to hold it in, but Ha-rin suddenly looked all slim and gazed at me wistfully... Gave me full-body chills, hard to endure. You know pufferfish? Her cheeks are all puffed like one normally? Always eating something. Anyway, extreme job.”
Wahahahaha! Even bigger laughter erupted. Pufferfish Ha-rin? She was top-three visuals among girl group centers.
“Ah! Oppa, seriously!”
Seo Ha-rin huffed, swinging at his arm.
“Nope, miss.”
But Seo Eun-seong smirked and dodged her swat slyly. The real-sibling roast battle heated the showcase to a peak. Who knew the visual siblings weren't just pretty but variety-show gold too? Fans and reporters snapped away on phones and shutters gleefully.
“Ah ha~ So your perfect business acting birthed iconic scenes? Great job. Final words? Actor Seo Eun-seong-ssi?”
Lee Ah-hyun, still giggling, wrapped it up.
Then, Seo Eun-seong dropped the smile for a serious expression, adjusting his mic.
“I was joking around earlier, but... truth is, Ha-rin, Eun-jin noona, Ah-hyun, Chae-yeon, and Min-ji—the Siren members poured blood, sweat, and sleepless nights into this album. I watched their efforts up close. It's a album they prepared so hard, so... please love and cheer for our Siren lots. Thank you.”
His warm words caring for sister Seo Ha-rin and members. Sincere support drew emotional applause from the audience.
“Oppa... thank you...”
Seo Ha-rin gazed at him misty-eyed. The Siren members' eyes reddened too.
Showcase ended, that evening. Korea's SNS and communities were plastered with 'Seo Eun-seong.' Especially the siblings' hilarious interview topped every entertainment outlet's main articles.
And the crowning MV. Siren's new track video hit 10 million YouTube views in just half a day.
The comments overflowed with global fans.
Seo Eun-seong lay in bed, scrolling endless comments.
“10 million views? Already?”
He felt dazed. Just months ago, he was an ordinary college student, over 100kg Bear Doll. Now, one MV had him captivating global K-pop fans as an actor.
I really... became an actor. Wild.
He turned off his phone screen, hand on his chest.
“Kyaa! Eun-jin unnie! Our MV hit 10 million fastest ever! Record!”
“This real? We hitting 100 million next?”
“We gotta! Eun-jin unnie!”
From beyond the door, Seo Ha-rin and Choi Eun-jin's voices, plus...
“Whoa... whoa... Eun-seong oppa... so cool...”
The Siren members' joyful voices echoed.