Reborn as a side character with a system

Chapter 1

[Synchronization complete… Character now in new host.]

Leo jolted awake, shooting upright in the bed as if he had been dragged out of a nightmare. His lungs struggled to catch up, breaths coming out heavy and uneven, while sweat clung to his face. His eyes were wide with shock, darting around as he tried to make sense of what had just happened.

“What… what was that?” he muttered, pressing a hand against his head as a dull ache pulsed through it.

It was then that he noticed something strange.

The bed beneath him didn’t feel like his. It was far too soft, almost swallowing his body whole, and far larger than anything he owned. The sheets were smooth—unnaturally smooth—and when he looked down, he realized they were made of silk, embroidered with delicate golden patterns.

Confusion crept in as he lifted his gaze and took in the room around him.

The space was enormous, far beyond the size of a normal bedroom. Tall, arched windows stretched along the walls, covered by deep crimson curtains lined with gold. Sunlight filtered through them, casting a warm glow across the polished marble floor. The walls themselves were decorated with intricate carvings and expensive paintings framed in gold, each one depicting noble figures or vast landscapes. A large wardrobe made of dark oak stood in one corner, while a neatly arranged table filled with glass bottles, scrolls, and strange glowing objects occupied another.

Everything about the room screamed wealth.

“…Everything here seems different…” Leo whispered, his voice uncertain. “Could I really have been sent into another world?”

For a brief moment, silence filled the air.

Then his expression shifted.

A grin slowly spread across his face, his earlier confusion melting into excitement. “This… is… awesome!” he shouted, throwing off the covers and jumping out of bed.

“Oh my, Sir Nolan! You shouldn’t be walking yet!”

The sudden voice startled him. A maid had entered the room without him noticing, quickly rushing to his side and gently guiding him back onto the bed.

“Nolan…?” Leo repeated inwardly, his thoughts racing. “Who’s that?”

His gaze shifted toward the maid as suspicion crept in. “And who is she…?”

At that moment, a translucent screen appeared before his eyes.

[Name: Isabella Hoshino]

[Age:38]

[Level: 64 (Tier-5)]

[Class: Assassin]

[Occupation: Maid]

[Overall Strength: 1200]

“Isabella… Hoshino…” he repeated silently, staring at the information. The name felt familiar—too familiar.

Then it clicked.

Hoshino was a character from a novel he had read. She had once lived as an assassin, taking on dangerous missions from powerful nobles. Later, she had vanished without explanation, only to reappear living as a maid somewhere unknown. Her story had always been shrouded in mystery.

A chill ran down his spine.

“Then how could I be here…?” he thought, his heart beginning to race. “Inside a book?”

“Young master, I will go fetch your medicine. Please rest,” the maid said gently before turning and leaving the room.

As soon as she exited, another presence filled the space.

“It seems you’re awake, young master.”

Leo turned toward the voice and saw a man clad in knight’s armor standing at the entrance. His posture was firm, his presence overwhelming.

“And who is he…?” Leo wondered.

Another screen appeared.

[Name: Ralph Valtieri]

[Age:43]

[Level: 78 (Tier-7)]

[Class: Knight]

[Occupation: Nolan’s Guardian]

[Overall Strength: 2800]

“Ralph…” Leo thought, narrowing his eyes. “He wasn’t supposed to appear this early…”

Blonde hair, red eyes, and a distinct scar running across his left cheek—there was no mistaking him. He was the knight who had appeared much later in the story, the one who had sacrificed himself to buy time for the hero’s party.

“But why is he here…?” Leo wondered. “And why is he my guardian?”

A deeper realization struck him.

“…Isn’t he also the one who killed Isabella?”

His thoughts spiraled further as another screen appeared before him.

[Host: Leo]

[Original Owner: Nolan Weldon]

[Age:18]

[Level: 1 (Beginner Tier)]

[Class: Mage]

[Health: 95/95]

[Mana: 45/45]

[Skills: Locked]

[Abilities: Locked]

[Strength: 5 | Speed: 5 | Agility: 5 | Intelligence: 5]

[Free Tokens: 5]

[Occupation: Heir to the Title — Lord of the Weldon Lands]

“…Weldon heir…” Leo murmured, a faint smile forming on his lips. “So that’s why…”

But the smile didn’t last.

His expression froze as realization hit him like a blow.

“…Wait.”

“The Weldon heir… dies at the very beginning of the story.”

Before he could fully process it, the system chimed again.

[Mission: Survive Assassination]

[Reward: Freedom of Life]

[Time Remaining: 24:00:00]

Leo’s body went rigid, his hands trembling slightly as he stared at the countdown.

“…Why him?” he whispered.

“Young master… are you alright?” Ralph asked, concern evident in his voice.

Leo forced himself to calm down, masking his panic behind a composed expression. “I’m fine,” he said before pausing. “Tell me… how long has Isabella been working here?”

Ralph frowned slightly. “Isabella? I’m afraid there is no one by that name, my lord.”

Leo’s heart skipped a beat.

“Then the maid who was just here—who is she?” he asked quickly.

“That would be Roselite, my lord. She has been your caretaker for nearly three months.”

“…Three months…” Leo repeated, lowering his gaze as the pieces began to fall into place.

Three months ago—that was when Isabella had disappeared from the world of assassination in the novel.

“So it really is her…” he thought. “But if I don’t know her reason, I can’t predict her actions.”

Ralph continued to observe him carefully, his expression growing more suspicious. “Young master… could it be that the poison you consumed has caused some side effects?”

Leo’s head snapped up. “Poison?”

“Yes. Yesterday, you were found collapsed while holding a bottle. It appears you had already ingested it.”

“I see…” Leo murmured, his mind racing.

“So the original Nolan drank poison… or was poisoned,” he thought.

He looked back at Ralph, his expression now serious.

“Ralph, I have an important task for you,” he said firmly.

The knight straightened immediately. “Anything within my power, young master.”

“Good,” Leo replied before beginning to explain his plan in careful detail.

As he spoke, Ralph’s eyes widened slightly.

“…Are you certain?” he asked. “Your body is still weak. This plan is dangerous.”

Leo met his gaze without hesitation. “It’s the best option we have,” he said calmly. “I didn’t drink the poison—I was poisoned. And if that’s true, then the next move is obvious.”

He paused, his voice lowering.

“If you don’t believe me… then take a gamble on me.”

A brief silence followed.

“Because if I’m wrong…” Leo continued, his expression unwavering, “…then I will renounce my claim as heir.”