Rei’s Promise

Chapter 1

– An Unexpected Encounter

That night, rain hammered down on the quiet corners of Tokyo. Streetlamps glowed dimly through the drifting mist, their light bending and scattering across the slick pavement. The streets were nearly empty, save for the endless patter of water against asphalt.

Rei Kurogane walked with measured steps, his long black coat swaying around his frame. His eyes were sharp and cold—the eyes of a man long accustomed to facing a merciless world. Yet deep behind that dark gaze lay something he never allowed anyone to see: fragments of a past as one of the most feared operatives in the shadows.

From a nearby alley came a sudden cry.

> “Let me go! Somebody, help!”

Rei froze, narrowing his eyes. Three rough-looking men were forcing a young woman into the darkness. She wore a simple uniform, her umbrella tossed aside, her face drained of color.

“Quiet! Do as we say if you want to live!” one of them growled.

Rei exhaled, almost in annoyance. Damn it… I wasn’t planning to get involved tonight.

But then his gaze fell on hers—wide, terrified, yet strangely untainted. Against his better judgment, his steps shifted.

He walked into the alley.

“Let her go,” he said flatly, his tone calm but carrying a chill that silenced the rain itself.

The thugs turned, then burst out laughing.

“Hah? Who the hell do you think you are? Trying to play hero?!”

Before they even had time to move, Rei advanced. In a blur, two of them were on the ground—one clutching a broken arm, the other doubled over, gasping for air after a strike to the gut. His movements were precise, fast, lethal.

The last man froze, trembling. “W-what the hell are you?!”

Rei’s expression remained blank. “I told you. Let her go.”

The thug bolted, leaving his companions groaning in the wet alley.

The girl collapsed, trembling. Tears streaked her cheeks.

“Th-thank you… I—” Her voice broke, and she fainted from shock.

Rei sighed. Why am I doing this?

And yet, he bent down, carefully lifting her light frame into his arms.

He carried her through the storm toward the nearest hospital. As she slept against him, her face softened. There were still traces of tears, but beneath them lingered an innocence he hadn’t seen in years.

For the first time in a long while, Rei’s lips curved into the faintest of smiles.

> I don’t even know your name. But something about you… feels different.

– The Mysterious Girl

The steady beep of a heart monitor echoed softly in the hospital room. White fluorescent lights filled the space with sterile calm after the chaos of the night.

Rei Kurogane sat in a chair tucked into the corner, arms crossed, his gaze fixed on the girl resting in the bed. Her hair was damp from the rain, her complexion pale, yet there was a softness to her features—innocence, fragile but strangely resilient.

Hours earlier, he’d almost walked away. And now here he was, keeping watch like someone who couldn’t quite bring himself to leave her alone.

> “Why the hell am I doing this?” he muttered under his breath. The answer, of course, wasn’t simple.

At around three in the morning, she stirred. Her lashes fluttered, her wide eyes blinking open with a mix of panic and confusion. She turned her head—and froze when she saw him.

“Uh… who are you?” her voice was weak, hoarse, yet still clear.

Rei didn’t answer immediately. Instead, he poured water into a cup from the bedside table and handed it to her.

“Drink.”

Her hands shook as she accepted it. After a sip, her gaze returned to him.

“You… you saved me, didn’t you?”

Rei gave the faintest nod. “I was passing by.”

“Passing by?” Her brow furrowed, then softened into a small, grateful smile. “If you hadn’t been there… I might have…” Her voice cracked, eyes glistening with fresh tears.

Rei looked away. “Don’t think about that. You’re safe now.”

A silence lingered between them before she whispered, “My name is Hana Hakari.”

She smiled faintly despite her exhaustion. “I don’t know who you are… but thank you.”

Rei studied her face for a moment. The name echoed in his mind. Hana Hakari…

“Rei,” he said at last.

“Hm?”

“My name. Rei Kurogane.”

Her eyes widened a little, then her lips curved into a fuller smile. “Thank you, Rei-san.”

The way she said it—gentle, sincere—stirred something deep in his chest. For the second time in years, his lips twitched into a fleeting smile.

The door opened. A nurse stepped inside, checking Hana’s vitals before glancing at Rei.

“She needs rest. If you’re family, you can stay. If not, it’s best to wait outside.”

Rei dipped his head slightly, rising to leave. But at the door, he paused. He looked back. Hana’s eyes followed him, unwilling to let the moment end.

“I’ll come back,” Rei said quietly.

Hana blinked, then her smile blossomed, childlike and pure. “I’ll be waiting.”

And for the first time in a long while, Rei felt himself tethered—not to duty, not to his past, but to someone.

– Hana’s Innocence

Morning sunlight filtered through thin curtains, warming the sterile hospital room. The cheerful chirping of birds outside contrasted with the usual cold atmosphere.

Rei stood in the corridor, a steaming paper cup in hand, the faint aroma of coffee drifting up. His expression was as unreadable as ever, but his thoughts were fixed on the girl inside the room.

He opened the door quietly. Hana Hakari sat upright on the bed, holding a small mirror, clumsily trying to tame her messy hair. Her efforts looked awkward, even silly—but something about the sight made her appear endearingly human.

Rei sighed. “What are you doing?”

She spun around, her eyes lighting up like a child caught in the act. “Ah! Rei-san! I’m just trying to look a little more presentable. I don’t want to look like… hmm… a raccoon that just crawled out of a trash can.”

The seriousness in her tone clashed with her innocent face, and Rei nearly smiled. He placed the coffee on the table. “You look… fine.”

“Really?” Her cheeks flushed. “I thought I looked ridiculous.”

He sat in the chair by her bed. “The doctor says you’ll need two more days of rest. Don’t push yourself.”

But Hana tilted her head, eyes filled with quiet hope. “Then… will you stay with me until I’m better?”

Rei hesitated. The simple request pierced through his usual walls. He lived by distance, by silence, but her gaze made it difficult to refuse.

“…I’ll try,” he answered at last.

Her face lit up instantly. “Yatta! I promise I won’t trouble you… or maybe just a little.” She covered her mouth, giggling at her own slip.

Rei looked away toward the window, concealing the warmth creeping into his chest. She was unlike anyone he’d ever known—innocent, naive, and yet that was exactly wh

at made her presence feel… warm.

> For the first time in years, a hospital room didn’t feel cold. It felt filled with light.