Saira is an ordinary office worker living a modest life. One day, she accidentally saves a young man who turns out to be Ryuichiro Ayashima, the heir to the prestigious Ayashima Group conglomerate. Desperate to escape an arranged marriage, he offers her an enormous sum to pose as his fake fiancée for three months.
Despite her hesitation, Saira accepts and enters his luxurious world. But she's not alone with him. There's Yano, his coldly efficient secretary who truly supports him; Asahi, a beaut
A Substitute Fiancée Falls in True Love - A Luxurious Cage, An Unfamiliar World
The next morning, Sara headed toward Ayashima Tower once again.
She hadn't slept the night before. The contract signature. The figure of five million yen. A fake fiancée. It all kept spinning endlessly through her mind.
*(Is this really the right choice?)*
The morning sun from the window flooded the room with light. The same sunrise as always. And yet, something had undeniably shifted.
Her footsteps toward the station should have been the same as yesterday, but they felt heavier somehow. On the train, the face reflected in the mirror looked like a stranger's.
She arrived at Ayashima Tower at 9 a.m. Unlike yesterday, today she bypassed the reception desk entirely and was guided directly to the private elevator. Holding the card key in her hand. Was that alone enough to change something?
Inside the elevator, Sara took a deep breath.
The 32nd floor.
When the doors opened, a hallway suffused with luxury stretched before her. The carpet was deep navy, and spotlights cast their light quietly from the ceiling. Several paintings hung on the walls. Were they authentic? No—nothing displayed in a building like this could possibly be fake.
"This way."
She heard Yano's voice. He stood at the far end of the corridor, his expression cold behind his silver-rimmed glasses, unchanged.
"Today, I'd like to introduce you to the instructor who will be overseeing your etiquette training. This is Reiko Kiritani."
Where Yano pointed, a stern-looking woman who appeared to be in her fifties stood waiting. Her posture was perfectly straight—her very bearing conveyed that *this person is different*. Her hair was white, nearly silver, pulled back tightly. When her eyes fixed on Sara, they held a sharpness that seemed to see through everything.
"It's a pleasure to meet you."
Sara bowed deeply.
"The course runs for two weeks. Table manners, deportment, conversation techniques for high society. I will drill everything into you thoroughly."
Kiritani's voice was sharp as a blade.
"Now, we'll move to the private salon."
The space Yano led her to was expansive. A room decorated in white and gold. In its center sat a dining table. Upon it lay several types of knives and forks. Glasses. Plates. Everything arranged with perfect precision.
"We'll begin with table manners."
Kiritani seated Sara at the chair.
"What sort of dining table have you eaten at until now?"
"Ah, well... a normal... household one."
Sara answered.
"In other words, you don't know how to use a knife and fork."
"Yes..."
Kiritani produced a sheet of paper. It was covered in countless lines with explanations written across it.
"Outside to inside. That is the fundamental rule. Your hands are dirty."
Sara looked down at her own hands.
"No, not with visible dirt," Kiritani continued. "With a lack of knowledge about high society. I will wash away that dirt in two weeks. Prepare yourself."
Three hours in the morning. How to hold a knife. How to hold a fork. How to hold a spoon. How to hold a glass. The angle of the spine. The position of the elbows. How to wipe one's mouth.
Each detail was meticulous. Each correction was harsh.
"That posture won't do. Keep your spine straight."
"Don't rest your elbows on the table."
"With that grip, you'll appear to be a woman without refinement."
Kiritani's corrections never ceased. Sara repeated her mistakes again and again. But each time, she corrected herself. Earnestly. Sincerely.
As she repeated the motions, sweat began to bead on Sara's forehead.
Noon arrived.
"Let's take a break," Kiritani announced. Sara rose slowly from her chair. Inside, exhaustion was accumulating.
*(Is this really necessary?)*
Part of her thought that. But she was the one who'd signed the contract. Which meant she had no choice but to see it through.
In the break room, cold water and a light meal had been prepared. Mineral water. Fruit. Small sandwiches. Everything was of the highest quality.
Sara drank the water. Her throat had been parched.
Then the wall monitor flickered to life.
It displayed the executive office on the 32nd floor.
*(What...?)*
Sara's gaze locked onto the screen. There were Ryuichiro and Yano, watching the salon's progress.
"She won't be able to do this."
Yano's voice came through the speaker.
"Look at her. That clumsiness. That ignorance. There's no way she'll pass in high society. If anything, the odds of her embarrassing herself are higher."
Yano's assessment was cold and clinical.
Meanwhile, Ryuichiro said nothing, simply staring at the monitor. His expression held a tangle of conflicting emotions.
"Ryuichiro-sama, emotional attachment is forbidden. This is business. Judge whether she can function as a fiancée or not."
Yano continued.
"She's hardworking."
Ryuichiro finally spoke. His voice was quiet, but it carried unmistakable weight.
"Look. No matter how many times she fails, she doesn't give up. That sincerity. That earnestness. That is her strength."
"But realistically speaking—"
"She'll see it through."
Ryuichiro's words cut off Yano's objection. There was a quiet certainty in them.
Yano's brow furrowed. Behind his glasses, his eyes gleamed coldly. Something like dissatisfaction flickered across his features—not merely a professional concern, but something else entirely.
*(Is he changing?)*
That was what Yano thought in that moment.
Meanwhile, in the break room, Sara had heard every word of the conversation.
*(Ryuichiro-san... believes in me.)*
Those words seeped into the depths of her chest.
Until now, had anyone ever truly believed in her? Her parents supported her, but that was because they were her parents. Her coworkers treated her well enough, but whether they truly believed in her was unclear.
But Ryuichiro. A man from high society, supposedly calculating. Her contractual partner. He believed in her.
*(Then I have to do this.)*
This might be a lie. This might be a fake engagement. But this trust felt real.
2 p.m.
When Sara returned to the salon, her concentration had deepened. Knives and forks. Posture. Smiles. Everything improved bit by bit.
Kiritani must have noticed the change. Her corrections remained harsh, but they seemed to have softened ever so slightly.
4 p.m.
The door opened.
Ryuichiro appeared.
Dressed in a black suit, Ryuichiro surveyed the salon quietly. For a moment, Sara's hand trembled as she gripped the knife.
"How is today's progress?" Ryuichiro asked Kiritani.
"Average pace. However, her persistence is worthy of note."
Kiritani's response held a faint note of approval.
Ryuichiro nodded and looked toward Sara.
"Could we speak for a moment?"
"Ah, yes."
Sara rose from her chair. In that moment, her exhaustion must have registered in Ryuichiro's eyes. He frowned slightly.
"Please don't overexert yourself."
His voice was quiet. But it carried unmistakable gentleness.
"You don't need to be perfect. Your sincerity is enough."
When she heard those words, something inside Sara's heart came undone.
*(This person... he really does care about me.)*
That was when she truly understood it.
From the salon's window, Tokyo's cityscape spread below. The sunset painted the city in amber light. In that view, Sara arrived at a single certainty.
*(I'll do my best. For him.)*
But she didn't know that Yano stood quietly in the corridor beyond, his eyes behind his glasses measuring the distance between Ryuichiro and Sara.
*(As I suspected...)*
Yano's lips moved faintly. He could feel it with certainty—an unforeseen variable was beginning to infiltrate his carefully laid plan.