Kang Joon-seo (Soo Ah's Stepbrother)
· Age: 30
·Profession: Corporate Lawyer
·Personality: Responsible, loyal, empathetic, and deeply devoted to family.
·Bio: Joon-seo is the son of Soo Ah's mother from her first marriage. Despite the complicated family tree, he considers Soo Ah his real sister and is fiercely
·protective of her. He was raised by his stepmother after his biological mother left. His warm nature and moral compass often put him in contrast with the darker shadows surrounding the rest of the family. Married to Ethan's elder sister, he believes in healing old wounds—but is completely unaware of the horrific truth behind the woman he calls "mother."
·Relationship with Soo Ah: Protective older brother figure. He sees her pain but doesn't yet understand the depth of it.
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The night had deepened, but the house wasn't asleep.
Soft light spilled from under Ethan Kim's door—the one directly connected to Soo Ah's room through the conjoined passage she had discovered on their wedding night.
She smirked as she quietly turned the knob and stepped inside, wearing a black oversized jacket and jeans. Her hair was loosely tied up, and she looked more like a curious college student than a trained killer or newlywed.
Ethan was at his desk, papers and digital maps spread before him. His laptop screen glowed with surveillance footage. Dressed in a black shirt, sleeves rolled up to his forearms, he barely glanced up.
"You're not good at knocking," he muttered.
"It's not breaking and entering if there's a door you left unlocked," Soo Ah replied sweetly, strolling in with her hands in her pockets.
He didn't answer. His eyes returned to the files, fingers tapping the desk in quiet rhythm.
Soo Ah tilted her head as she looked around the room—sleek, minimal, cold. Everything was arranged perfectly, like the man himself.
Then her eyes drifted to the small conjoined door between their rooms—the one he had ignored since the day she pointed it out.
Her smirk widened.
"You know…" she began, sauntering toward it, "this little door feels kind of symbolic."
Ethan sighed without looking at her.
"Don't start."
"I mean, come on. Two rooms. One secret door. So poetic. Almost like fate wanted us to be awkwardly close."
"It's just architectural laziness."
"Or maybe the universe was shipping us before we even met," she teased, leaning against the doorframe.
Ethan finally looked at her—just briefly, his eyes sharp but tired.
"Why are you here?"
"Bored. Hungry. And maybe a little fascinated by your entire 'cold-blooded businessman by day, underground assassin by night' vibe."
She wandered closer to his desk, peering over his shoulder.
"Are those blueprints? Planning a hit or building a new kitchen?"
Ethan reached over and closed the laptop slowly.
"You really don't care about personal space, do you?"
Soo Ah grinned.
"You married me. That door comes with the package."
He stood suddenly, the chair scraping back.
"Then maybe I should lock it."
She leaned in, eyes gleaming with amusement.
"You can try. But if you do, I'll just make another door."
They stared at each other—her full of fire, him an unmoving wall.
Then, without waiting for dismissal, she turned and strolled back toward the conjoined door.
"Goodnight, Ethan."
"Stay out of my room."
"Only if you stop making it so interesting."
The door closed gently behind her, leaving Ethan in the silence of his own controlled chaos—now slightly, maddeningly off-balance.
[ Ethan used to live in a apartment but for Soo -ah's comfort he decided to buy a penthouse and he had no idea about the conjoined room. He also discovered it with Soo -ah.]
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It was a quiet afternoon in the Kim estate's private dining room.
Sunlight filtered through the tall windows, casting a warm glow over the long wooden table. A delicate arrangement of plates and silverware sat untouched as the kitchen staff prepared lunch just beyond the doors.
Ethan sat at the head of the table, posture straight, a tablet in one hand, reading through an encrypted document. His sharp gaze lifted when Soo Ah entered—wearing a loose beige sweater and black jeans, her hair tied into a messy bun.
"You're late," he said without looking at the time.
"It's not fashionably late if I'm married to you," she replied, sliding into the seat beside him. "You'd probably time my heartbeats if you could."
He didn't respond.
Instead, his eyes flicked over her frame. Slender. Almost too slender. Her wrists looked delicate beneath the sleeves.
He set the tablet aside.
"You've lost weight," he stated plainly.
Soo Ah blinked, surprised.
"What?"
"You're already too thin. You need to eat more."
She grinned. "Aw. That almost sounded like concern."
"It's not," he replied calmly. "You're no use to me half-conscious on the floor because you skipped breakfast."
Before she could answer, the servers entered with dishes—steamed dumplings, spicy beef stew, kimchi pancakes, rice, and multiple side dishes, all steaming and aromatic.
Soo Ah's eyes sparkled.
"Finally."
She reached forward like a child at a festival, piling rice, stew, and every side dish onto her plate with zero hesitation. Ethan blinked, just once, as she filled a second bowl. And a third.
He watched, slowly lowering his chopsticks, as she started eating—enthusiastically, joyfully, like someone who hadn't tasted food in days.
"You said I should eat," Soo Ah said between bites, noticing his frozen expression. "I'm just being obedient."
Ethan stared at her.
"You eat… like a soldier after war."
"Flattering," she said, slurping noodles. "But seriously, my metabolism's a beast. I burn it all off with anxiety and a bit of murder."
Ethan pinched the bridge of his nose.
"Remind me why I agreed to marry you?"
Soo Ah flashed him a noodle-filled smile.
"Because I'm a delight."
He didn't smile. But the corner of his mouth twitched.
Just slightly.
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. Kim Yeon-jin (Ethan Kim's Elder Sister)
·Age: 32
·Profession: CEO of a high-end fashion brand
·Personality: Assertive, sharp-witted, emotionally intelligent, and warm beneath a polished exterior
·Bio: The only member of the Kim family Ethan once trusted. Yeon-jin was devastated when their family blamed Ethan for their younger brother's death. After marrying Kang Joon-seo, she slowly reconnected with her brother through him. Though Ethan has emotionally distanced himself, Yeon-jin still tries to look out for him. She has grown fond of Soo Ah, unaware of her secrets, and sees the marriage as a second chance for Ethan to heal.
·Relationship with Soo Ah: Supportive sister-in-law, hoping to build a genuine bond.