[At the same time]

As they stood at the crossroads, unsure of which direction to take, Ryu's voice broke the silence. "I think she said it was this way," he said, pointing towards one side of the crossroads. Ryu had asked the ice cream shop lady for the directions to Aroshi's house discreetly afterall.

Kai nodded in agreement, and the group followed Ryu as he led the way. Eventually, they arrived at a beautiful yet slightly unkempt house. With cautious steps, they quietly made their way through the front gate.

Upon reaching the front door, they noticed three paira of slippers neatly arranged outside, indicating that someone was already inside. Kai whispered in a hushed tone to Ryu, "Someone is in there already."

Ryu looked around uncertainly, then turned back to Kai and whispered back, "Well, what do you want me to do?"

The group exchanged nervous glances, their eyes flicking back and forth between each other and the front doors.

"Should we go in?" Himeko asked, her voice barely above a whisper. Sebiki nodded in agreement, replying quietly, "We've come so far. No mistakes." With determined steps, she quietly pushed open the front door, and the rest of the group followed suit.

Once inside, they carefully removed their shoes and held them in their hands, mindful of any squeaking floorboards that might betray their presence. Luckily, the floor remained silent as they made their way further into the house, their hearts pounding with anticipation and apprehension.

[In the dark area, at the same time]

When Kavei regained consciousness, the first thing he did was check his watch to figure out how long he was out for. And as he had thought, he couldn't see anything. Using the wall for support, he stood up and began to feel along its length, searching for any source of light.

His fingers brushed against a plug board, and he struck it harshly in the hopes of finding a switch. Dim lights flickered to life, illuminating the small room he found himself in. Surveying his surroundings, he realized he was facing a dead wall, devoid of any decoration or features.

A sudden sensation of wetness on his forehead drew his attention, and he instinctively touched it, finding blood. Recalling the pain, he turned around and noticed a heap of sacks piled up in one corner of the room. It became clear that he must have attempted to navigate through them, only to lose his balance and collide headfirst with the hard cement wall.

Confusion gripped him as he tried to make sense of his situation. "What...where is this?" he muttered to himself, his head throbbing from the wound. Despite the blurriness in his vision, he managed to remain standing, pressing his hand against the wall for support.

In his distress, Kavei called out to his friends, hoping for some answers. "Benio nii...? Miyasi nee...? Saira nee...? Where are you all? Where am I?" His words echoed in the empty room, but there was no response, leaving him alone with his thoughts and growing apprehension.

"Hey Benio. What a coincidence. We just finished the rooms in the end. Nothing there," Miyasi said, breaking the silence.

"I checked the second room...thrice actually. But nothing," Benio replied with a hint of frustration evident in his voice.

Saira sighed in disappointment, her shoulders drooping slightly.

"Hey. We still have three rooms left, you know. One to the left and two to the right," Miyasi reminded Saira, trying to maintain their optimism.

"Hey! Aren't they Kavei's senior friends?" Sebiki whispered to the group from their hidden position behind the walls near the staircase.

"They are," Kai confirmed quietly, his eyes fixed on Kavei's friends.

"So they really did come today. What are the chances?" Himeko remarked, a half-smile forming on her lips. "Do we catch them now?" she asked Sebiki, eager for action.

Sebiki lightly tapped Himeko's head. "Hey! Why?" Himeko protested.

"I mean I would have hit harder if we weren't in hiding," Sebiki explained.

"What?" Himeko's confusion was evident.

"Himeko, we are not here to spy or catch them in their little act. We need to use their clues, outsmart them, and get one step closer to finding the culprit," Sebiki clarified.

"What?"

"We won't catch the culprit. We'll show Kavei that we know who they are before he finds out," Kai interjected, joining the conversation between the two girls.

"But Kavei is a detective," Himeko pointed out.

"That is why we are here, stupid," Sebiki retorted, her tone firm.

As they continued spying on Kavei's friends discussing their next steps, Miyasi raised a concern about Kavei's whereabouts.

"But Benio, where even is Kavei? He should be out by now, yeah?" she asked, her brows furrowed in worry. Benio shrugged, equally puzzled by Kavei's absence. They decided to check the nearby room just in case.

However, their search turned up empty, and panic began to set in.

"What the...do people disappear in rooms just like that?" Saira exclaimed, her nails now gripped between her teeth in anxiety.

Miyasi's sharp eyes caught sight of broken tiles on the balcony. She cautiously approached them, illuminating the dark hole with the light from her phone. To their surprise, they discovered stairs leading deep down.

Without hesitation, Miyasi stepped forward, followed closely by the others. With each step down, they descended further into the unknown, driven by their determination to uncover the truth.

Kavei's eyes caught sight of something protruding from between two of the sacks. With cautious movements, he crawled towards it, his curiosity piqued. As he reached out and carefully pulled the object free, footsteps approached him, causing him to tense up.

Shoving the item into his pocket, Kavei stood up, ready to defend himself if needed. "Kavei...?" a soft voice called out from the darkness.

"Miyasi nee...?" Kavei replied, recognizing the voice. His fists relaxed slightly at the familiar sound.

"Kavei! It really is you!" Miyasi exclaimed as she descended the stairs. However, upon seeing Kavei's injured state, her expression turned to one of concern. "What... happened?" she asked, her voice filled with worry.

Kavei placed a hand on his forehead, downplaying his injury. "Just... a little wound," he reassured her. Benio and Saira soon joined them, their concern evident.

"Oh god. Are you okay?" Benio asked, his eyes scanning Kavei for any signs of serious injury. Kavei nodded in response. "But where is this?" he asked, his confusion apparent. "I remember walking onto the balcony, and the next thing I knew, I was here..."

"The balcony, yes. I think this was supposed to be a secret room, but you got in the wrong way," Miyasi explained, recalling their surroundings.

"Yeah. I fell here," Kavei admitted with a slight chuckle, trying to lighten the mood.

Meanwhile, upstairs, Sebiki and the others strained to make sense of the voices echoing from below.

"What are these sacks?" Saira questioned, directing Kavei's attention to the mysterious heap.

"I haven't checked yet," Kavei replied, slowly approaching the sacks. As he brushed his hand against one, he noticed a strange stickiness. With caution, he pulled the nearest sack away from the pile and undid its rope closure.

"What is that dark liquid...? It smells weird," Benio remarked, covering his nose with his hands, followed by Saira and Miyasi.

"It's... blood," Kavei confirmed, the realization dawning on him as he sniffed the liquid that had gotten on his hand.

Their collective gaze shifted to the heap of sacks before them, horror evident in their widened eyes. Despite the unsettling discovery, Kavei remained surprisingly composed compared to his friends.

"Aaaahh!!!" Miyasi's piercing scream shattered the tense silence, her hands flying to her face in shock. The sound echoed through the house, alarming the friends upstairs, who wasted no time in rushing outside the house.

Miyasi then fell on her knees, completely terrified. Her eyes were on the verge of falling out when Benio and Saira grabbed her by her shoulders, a tight grip, trying to give her what solace they could.

After a while, Benio emerged from the house and proceeded to purchase a bunch of plastic covers from a store nearby, willingly paying more than necessary for them. With the covers in hand, he returned to the house where Kavei awaited him.

Watching from a distance, Kai, Himeko, Ryu, and Sebiki observed Benio's actions as he exchanged cash for the plastic covers and returned to the house.

Inside, Benio handed the covers to Kavei, who stood up despite his swaying legs caused by the wound on his head. With determined focus, Kavei began opening each sack, attempting to collect samples of the dried blood within. However, the blood had solidified over time, resembling frozen blocks rather than liquid.

"Blood can't be stored for too long. When thawed, the antifreeze is removed under sterile conditions. So at some places blood can be stored for 10 years, but..." Kavei paused, the weight of the situation sinking in.

"How long has it actually been?" Saira inquired, her voice tinged with concern.

Undeterred by the challenge, Kavei scooped the blood out with his bare hands, depositing it into the plastic covers for sampling. Each cover was meticulously labeled with letters and then numbers, totaling fifty-three bags by the end.

Exiting the house, Kavei carefully stowed the plastic covers in his bag, his friends walking along side him.

"They are for sample analysis. We will definitely find something," Kavei told Saira who seemed to have held the question in her head.

Benio carried a visibly shaken Miyasi, settling her onto a nearby seat outside a snack shop. Meanwhile, Himeko, Kai, Sebiki, and Ryu remained nearby, behind the said shop, their voices hushed.

"Oh my god! He is hurt!!" Kai whispered as he began to come out of hiding to rush to Kavei when Sebiki held him back by grabbing his arm.

"Control you emotions," she told him. Kai grit his teeth as he stepped back next to her, his eyes not looking away from the wound he could so clearly even from a distance.

"Are you going to get them assessed?" Benio inquired, prompting Kavei's response.

"Yeah. A blood test," Kavei confirmed, his tone serious.