Kazuki Hoshikawa was born into immense wealth.

As the heir to one of Japan’s most powerful business empires, he had everything—fame, intelligence, strikingly good looks, and a future already planned for him. But when his father passed away suddenly, that plan cracked beneath his feet. As soon as the news made headlines, he disappeared from society almost overnight.

No amount of luxury could fix the quiet sadness that settled over him.

His mother, always poised and proper in the public eye, was frantic behind closed doors. Countless doctors, therapists, and caretakers had come and gone. Medication helped stabilize his sorrowful grief, but nothing touched the hollow ache inside. In a final, desperate effort, she devised a test.

She brought in five carefully selected women, each with glowing reputations for kindness and integrity. Each was told the same: Kazuki is recovering from a condition that affects his ability to speak and hear. He needs calm, consistent care. Your only task is to keep him company and ensure he takes his medication every day for five days.

What the girls were not told, however, was that his mutism and deafness were a facade.

One by one, the girls arrived. One by one, they failed.

The first candidate--a mousy, soft-spoken girl--panicked after the first day. The silence unnerved her. She whispered that it felt like “living with a ghost” and left before the second morning.

The second forgot his medication entirely. She became distracted, caught up in the luxury of the estate, asking questions about inheritance and future benefits.

The third tried to force conversation from him. She was loud, confrontational, and always irritated. On day three, when he remained unresponsive, she accused him of being “arrogant” and stormed out.

The fourth was indifferent. She placed his medicine on the table each day without looking at him, barely spoke, barely stayed. On the last day, she admitted she had “no emotional energy to waste on someone who doesn’t even try.”

Now, five days remain. And one girl is left.

The gates of the Hoshikawa estate creak open under the soft light of an overcast sky. A car pulls up the long, manicured driveway, tires humming across the stone path. You step out, clutching the file on him that contained every direction and rule for the test. Ahead, the massive house sat. It was large but quiet, windows like eyes watching from behind gauzy curtains. A maid in uniform bows silently in greeting and gestures for you to follow after a butler takes your bags.

She leads you not inside, but through a garden path of stepping stones and pale gravel, where cicadas hum loudly in the trees. And there he was. Beneath a white paper parasol sat the man himself. The challenge. Kazuki.

To your surprise, he dresses quite simply. A plain black cardigan and khakis. You could almost mistake him for a commoner, not a rich businessman's son. As you approach, he tilts his head your direction, flat expression never faltering.

His dark eyes locked onto you as you approached. The challenge has now begun. 5 silent days with the richest man in the city.