Episode 01
“…Mom.
When my brother gets better, this time… please throw me a birthday party.”
It was a hospital drenched in the relentless heat of midsummer.
Five-year-old Jin Seo-eun clutched her mother’s hand tightly and made her wish.
She was a child born for one purpose alone—to save her second older brother, Hyu-seok.
They called her the savior sibling.
The cord blood she donated at birth ultimately proved ineffective. And in the year she turned five, she underwent a bone marrow transplant.
Her body was painfully small and fragile, small enough to require full anesthesia. Yet there was no trace of fear on the girl’s face.
No—if anything, Seo-eun looked excited.
She believed, without a shred of doubt, that once her brother recovered, her family’s love would finally reach her as well.
“Of course. Once your brother gets better, you can go to kindergarten.
You’ll make friends, learn ballet, eat birthday cake…
You understand, right?”
“Hehe. Really? I really want to learn ballet!”
Going to kindergarten.
Making friends.
Eating sweet birthday cake.
Things that were utterly ordinary to others had never once been allowed to Seo-eun.
Her life was nothing like that of children her age.
Because her immunity could not weaken, she spent most of her days confined indoors. The only time she was permitted to go outside was when she visited the hospital.
In spring, she had to avoid insect bites.
In summer, food poisoning.
In fall and winter, even a simple cold.
Not even the smallest wound was allowed.
The reason was simple—
she always had to be ready to give healthy bone marrow to her brother.
“Brother Hyu-seok! Don’t worry!
I’ll make you better—no matter what!”
Remembering her brother gasping for breath inside the sterile room, Seo-eun quietly climbed onto the operating table.
Many years passed.
Contrary to Seo-eun’s desperate wish, Hyu-seok’s illness returned—again and again.
With each passing year, her parents grew visibly thinner, more exhausted.
Seo-eun blamed herself entirely for the relapses.
If only she had eaten better.
If only she hadn’t cried at night.
If only she had prayed harder.
“If only I could’ve given him better bone marrow…”
Simply being alive while her brother suffered felt like a sin.
The young girl gnawed at herself dozens of times a day.
“Mom, I’ll give him my marrow again.
Please—schedule the surgery right away!”
“That’s… difficult, Seo-eun.”
“Why? Why is it difficult? Look at me! I’m healthy!
I eat better now—I’ve even gained weight! I’m really fine!”
“…Seo-eun, stop. Please stop.
Mom is exhausted too.”
Later, she learned the truth.
Receiving bone marrow from the same donor more than once was extremely rare.
Even if it were possible, doctors said her young body might not endure it again.
From that day on, her mother never mentioned bone marrow.
Instead, she quietly rolled up Seo-eun’s sleeve—and took her blood.
Even when her veins burst and bruises bloomed purple, even when anemia struck again and again, needles were always driven into her wrist.
She never complained.
Never cried.
Never said she was tired of it all.
Seasons passed—flowers bloomed, leaves fell, snow returned.
Accepting her fate without protest, the girl grew into a woman of twenty-three.
By some cruel twist of fate, Hyu-seok survived after receiving marrow from another donor.
The results, however, were far from good.
Relapse.
Again. And again.
“Seo-eun… sometimes I feel like a parasite.
Like I should’ve died a long time ago.”
“Don’t say that. Medical technology has advanced.
The doctor said we can try another transplant.”
Miraculously, Seo-eun was given another chance.
To give her bone marrow—once again—to the brother she loved.
Born as a savior sibling, Seo-eun had the highest HLA compatibility with Huseok.
Meaning no one in the world was a better donor than her.
When she finally opened her eyes after enduring the long surgery, her mother smiled brighter than ever and embraced her tightly.
“Seo-eun.
This time, the engraftment rate is 100%.
It’s really over now.
You’ve done so well… truly.”
“…Mom.”
“Yes, sweetheart?”
“Then… can I finally…
have a birthday party?”
Twenty years ago.
And even now—
Seo-eun’s wish had always been the same.
✦✦✦
The lobby of Korea University Hospital.
Among the countless patients and guardians passing through, one man stood out unmistakably.
Skin pale as porcelain, sharp single-lidded eyes.
Sterile gauze slapped carelessly onto his forehead, split lips, thin silver rings on his right index and ring fingers, and a leather rider jacket clinging to him like blood.
At first glance, he looked like trouble incarnate.
And yet—he was impossibly handsome.
Ignoring the stares around him, Kwon I-do took a sip of coffee.
He was long used to attention.
His gaze was fixed on only one place.
The Hematopoietic Stem Cell Transplant Consultation Center.
Through the half-open door spilled the coordinator’s frantic voice.
“Ma’am, this is no longer possible!”
“My third child has the same blood type as Hyu-seok!
You know that means we can do a kidney transplant!”
“Seo-eun could be in real danger!
Hyu-seok is precious—but so is Seo-eun!”
“How many times do I have to say it?!
Seo-eun was born to save Hyu-seok!”
The shrill voice echoed through the room.
“That girl has a strong will!
She’d pretend to die if it meant saving her brother!
Seo-eun—say something!”
The young woman who had remained silent finally lifted her head.
Hollow shoulders.
Vacant eyes.
Tightly pressed lips.
With no trace of vitality, she spoke slowly.
“Doctor… I’m fine.
I can give him my kidney.
As long as my brother lives…”
I-do’s hand froze mid-sip.
What kind of idiot lives like that?
Startled by the attention, a nurse hurriedly shut the door.
“Kwon I-do! Is this hospital your living room?!
How many times do I have to tell you to stop riding motorcycles!”
As the live-action tragedy ended, a man in a white coat approached him.
Kim Yoon-jae—his high school classmate and a neurosurgery resident.
“You were watching the transplant center?”
“Pretty entertaining.”
“Reality’s more brutal than drama.”
As casually as reading the morning news, Yoon-jae continued.
“That family’s famous here.
Twenty years of cord blood, bone marrow, peripheral blood…
Now they want her kidney too.
‘Draining her dry’ isn’t an exaggeration.”
I-do’s gaze returned to the closed door.
A woman who had ground her entire life away for the sake of blood ties.
Slowly, the corner of his mouth lifted.
He chuckled—unaware that his torn lip was splitting further.
“Are you insane? Why are you laughing?”
“It’s just… funny.”
“What part? You’re seriously a psychopath.”
Well…
Looks like there’s someone out there with a life just as pitiful as mine.
