Siblings with No Life Get Summoned to Another World as Detectives

Kai slowly opened his eyes, still half asleep. He was in his bed… but something felt strangely warm beside him. As his vision cleared, he realized that Mei was lying right next to him, curled up like a cat.

"You're too close…" Kai mumbled in a sleepy voice, gently moving her hand that was wrapped around his waist.

"Mmhm… I know…" Mei murmured through a half-sleep, a drop of drool sliding down her cheek straight onto the pillow.

Kai yawned silently, then let out a long, tired sigh. "You're really… hopeless," he murmured, giving her a gentle shove with his foot, pushing her off the bed.

THUMP!

Mei tumbled to the floor and after a few seconds squeaked: "Owieee…"

"You know, I thought the state of war would be… well… more war-like… But nothing's really happening…" Kai muttered, speaking to himself in a disappointed tone.

"It's only been a week…" Mei shot back quietly, lying on the floor.

Kai sat up, then suddenly swung his legs over the edge of the bed. His feet landed on the floor right next to Mei's head, causing her to make a tiny grimace, but she said nothing. He stretched, then sluggishly headed toward the bathroom.

Mei, with a short sigh, lifted herself off the floor. As she stood, she brushed the dust off her clothes with her hand, then, without a word, followed him.

Kai took his toothbrush without hurry, let a thin stream of water wet it, and squeezed out some toothpaste. He opened his mouth, clenched his teeth, and began brushing.

Mei paused at the doorway, leaning her shoulder against the frame. She watched him silently, her gaze neither friendly nor hostile, but somewhere in between — as if trying to understand what her brother really meant to her at that moment.

Feeling her piercing gaze at the back of his head, Kai slowly turned toward her. Their eyes met, locked in a deadpan stare: the brother brushing his teeth, and the sister standing in the doorway.

Kai pulled the toothbrush from his mouth. Foam had gathered at the corners of his lips and was dripping down his chin as he tried to speak. "Do… you need something?" he asked, his voice muffled by the foamy bubbles, his words slurring.

Mei looked at him for just another moment, a spark lighting in her eyes as an idea struck her. With a swift movement, she snatched the toothbrush right out of his hand. Her figure spun abruptly, hair flying in the air, and then, in a hurried step, she dashed into the hallway through the bedroom door.

Kai froze, staring blankly at the empty spot where his sister had just stood. It took him a few more seconds to process what had just happened, then, with foam still dripping onto the floor, he barely murmured: "Huh?"

The next moment, as if his brain finally kicked in, he ran after her. "Give me back my toothbrush!" he shouted.

As she ran, Mei kept glancing left and right, searching for the best escape route. When she reached the main stairs, she didn't even pause to think. Instead of going down normally, she sat on the railing, wrapped her arms and legs around it, and began to slide down.

Her brother was right behind her, out of breath, watching his eighteen-year-old sister in a crumpled pajama slide down the stair railing with his toothbrush. The foam gathering in his mouth started to bother him. He spat onto the floor and dashed down the stairs without hesitation. "Come back here!" he shouted.

Mei landed below, still breathless from the adrenaline, and sharply veered toward the living room. She hid behind the couch, her heart pounding like a drum. She gripped the toothbrush tightly, a smile quivering on her lips.

"Where are you now?" Kai asked, passing by the living room.

Still crouched behind the couch, Mei held the toothbrush out in front of her like it was some sacred relic. Her eyes followed every detail. "Kai had it in his mouth…" she whispered thoughtfully, a drop of drool slowly sliding from the corner of her lips.

Just at that moment, Lily was passing through the living room. Her steps halted as soon as her eyes caught the scene: Mei, in her pajamas, crouched behind the couch, her eyes wide open, holding Kai's toothbrush tightly in her hands, staring at it as if she had discovered treasure.

Lily tilted her head, confused. She paused, thinking about asking what could possibly be so special about a simple toothbrush.

But before she could speak, Mei, without a moment's hesitation, suddenly shoved the toothbrush into her mouth and started brushing her teeth.

Lily froze, her eyes wide, her jaw slightly dropped.

"Kai's toothbrush…" Mei mumbled through the layer of foam, her words garbled and muffled. Foam dripped down her chin as her mouth stretched into a degenerate grin. "Hehehehe…"

"Huh?" Lily whispered softly, her voice hesitant and full of bewilderment, carefully watching as Mei, with that strange gleam in her eyes, used Kai's already-used toothbrush.

"The toothbrush… Kai's toothbrush…" Mei muttered, her degenerate grin widening further.

At that moment, Kai burst into the living room. He ran to the couch and, without hesitation, grabbed the toothbrush from Mei's hand, but she didn't budge an inch. They began tugging on the toothbrush from both sides, foam flying from Mei's mouth onto the floor.

"Give it back!" Kai shouted.

"Never!" Mei yelled.

Kai stopped and studied Mei carefully, then his eyes landed on the layer of white foam clinging to her lips. "Did you… use my toothbrush?" he asked, his voice a mixture of disgust and surprise.

"Yes…" Mei replied, her tone quieter, almost guilty. Her hands still gripped the toothbrush tightly as her smile slowly stretched through the foam.

"Then I don't want it anymore!" Kai yelled, letting go of the toothbrush.

"Yay!!!" Mei shouted, hopping slightly in place, clearly thrilled with her little victory. Her eyes sparkled with excitement.

Kai paused for a moment, thinking, and then suddenly reached out and grabbed the toothbrush again. "Wait… actually, I do want it. Give it back!"

Lily stood to the side, more bewildered than ever as she watched the brother and sister wrestle over a simple toothbrush.

"Give it back…" Mei said, her voice tense and full of determination as she pulled harder. "Take this: SMACK!" she suddenly shouted, punching the couch and leaving a hole in the upholstery. The sound of tearing and impact echoed through the room as small pieces of fabric and foam bounced on the floor.

The siblings instantly froze and looked at each other, their eyes meeting in a brief moment of confusion and mild embarrassment. Only then did they notice Lily standing to the side, her face a mix of shock and disbelief.

At the same time, both of them let go of the toothbrush. It fell onto the couch, bouncing a few times before finally coming to rest. Kai slowly moved a pillow, keeping eye contact with Lily, carefully placing it over the hole in the couch.

Without further hesitation, they both turned and ran away.

Lily sighed, placing her hands on her hips and leaning slightly against the doorframe. "What am I supposed to do with them…?" she whispered.

The brother and sister rushed abruptly toward their room. The moment they stepped into the narrow hallway, they ran straight into Vorenhart. He stood upright, his arms folded by his sides, and his cold gaze pierced anyone who dared to stand in his way.

They froze automatically, their eyes meeting his.

"Well, well… look who we have here…" Voren began, his voice simultaneously gentle and threatening.

"Oh… Voren… Sorry for… for the war… and everything else that happened…" Kai mumbled.

Voren raised an eyebrow sharply and gave a faint smile. "It's fine…" he said, his voice calm, almost satisfied, "I can stop it easily… with the diary."

Mei stepped forward, her shoulders sagging slightly in a subtle motion, speaking calmly but firmly: "Then you should know… we have no trace of the diary."

Voren hissed softly, like a snake. "Check Frieren's room… Maybe he had something of importance…" he said.

"Right away!" Kai exclaimed, grabbing his sister's hand and almost dragging her up the stairs toward Frieren's room.

Mei pressed the doorknob, and the door swung wide open. They immediately stepped inside, their eyes scanning every detail of the room, searching for the slightest clue that could help them.

They searched tirelessly, examining every paper, every folder, every drawer and box. Half an hour later, their efforts were in vain.

"This is hopeless…" Kai said, his tone heavy and frustrated as he flopped onto the bed.

Mei sat beside him, lowering her head, and quietly murmured: "Dead End…"

"What now…?" Kai asked as his eyes scanned the room for any solution.

"…" Mei remained silent, just lowering her shoulders quietly, unsure of what to say.

Silence filled the room as the seconds passed almost unnoticed. But only moments later, the door quietly opened, and Lily stepped inside.

Instead of being surprised by her arrival, Kai felt only irritation. "Why are you everywhere!?" he exclaimed sharply.

Lily flinched slightly at his tone, her face turning faintly red, and at that moment, she looked vulnerable. "Um…" she murmured, struggling to find the right words to explain her presence, her gaze shifting between Kai and Mei.

"Lily…" Mei began, her voice quiet but carrying a note of curiosity.

"Yes?" the maid asked, tilting her head slightly to the side, with a smile more curious than serious.

*Where are Doggie and Kitty? I haven't seen them in forever…" Mei asked, her eyes lighting up as she glanced at the bed, then quickly lunged onto it beside her brother.

Lily lowered her gaze to the floor, her expression restrained, but fear of the siblings subtly shone through her eyes. "They ran away…" she said softly.

Disappointment flashed across Mei and Kai's faces, but they tried to hide it. Their eyes quickly averted, and their shoulders sagged slightly.

"One more question…" Mei began, her voice becoming more serious. "What did Frieren do when he wasn't at the White House?"

"Um… You mean in his free time… Well… I think he has his own house, somewhere near the forest…" Lily said, her voice hesitant, her eyes wandering around the room. Her words were quiet but significant for Kai and Mei.

"Do you know where?" Kai interjected eagerly, his heart pounding at the thought that this might be the clue they had been waiting for.

"I think he gave me a map to it…" Lily admitted, lowering her gaze slightly.

Kai and Mei smiled, exchanging a look full of anticipation.

⬛ ⬛ ⬛

"That should be it…" Kai said, averting his eyes from the map and focusing on the small wooden cabin standing at the edge of the forest. His eyes took in every detail of the exterior: the cracked door, the faded planks, and the roof that creaked under the gentle breeze.

"It should be…" Mei repeated, her voice quiet but full of expectation. Her eyes followed every shadow the forest cast on the cabin.

Wordlessly, they slowly made their way to the cabin. The old door creaked as it opened, echoing through the silent forest.

Inside, the floor was covered with scattered papers, weapons, and various odds and ends — candles, a compass, spoons, even shoes and old socks.

"Looks like someone's already tried to find something here," Kai said, his gaze sweeping across the room, trying to make sense of the chaos around him.

"Let's search too…" Mei added, her voice determined, her eyes sparkling with curiosity as she began to comb through the cabin with tremendous energy.

At her words, Kai sighed deeply, feeling the weight of the task ahead. He wasn't thrilled about searching through so much space. "But…" he started, his voice weak as he tried to avoid extra effort. He had already spent half an hour combing Frieren's room in the White House, and now an even bigger mess awaited him.

His sister just looked at him, her eyes saying it all: a mix of mild annoyance and firm determination. That simple but piercing look was enough to make Kai reluctantly start working.

They searched the room for hours, moving everything in their path, tossing socks, dirty laundry, old books, and boxes, seeking any clue that could reveal where the diary was hidden.

Finally, Kai came across an old chest, dusty and dark, tucked in the corner of the room. He opened it carefully, but inside was nothing. He examined it from the outside, inspecting every detail, then opened it again. Something about the chest felt strange.

It appeared larger on the outside than on the inside, and Kai felt his pulse quicken as he studied it. His hands gently rested on the surface, fingers pressing lightly against the wood.

He tapped the bottom a few times, listening to the echo that revealed its secret. The sound was different from the rest of the chest — empty and hollow. "False bottom…" he thought, feeling a chill run down his spine.

Without hesitation, he slammed his fist onto the bottom. The wood cracked with a short, squeaky sound, and part of the bottom broke away under his hands.

Beneath it… was something Kai could never have imagined. It was—