Part 10: The Last Matching Factor
Mikasa spun around in utter shock. Standing right at the entrance of the hallway was Mimi. She had followed them all the way from the house, her small sandals dusty from running down the streets.
"Mimi?!" Mikasa gasped, her hands flying to her mouth. "You were supposed to stay home!"
Mimi ignored the scolding, taking three slow, hesitant steps toward Dr. Ken. Her hands were clenched tightly at the sides of her shirt, her chest heaving as she stared up at the doctor with fierce, desperate determination. Even though Haruto was technically her cousin, Mimi had always looked up to him as her true older brother. The thought of losing him terrified her to her core.
"Take mine..." Mimi pleaded, her small voice shaking as she held out her tiny arm toward Dr. Ken. "Please... take my blood for Haruto-niichan..."
Dr. Ken looked down at the five-year-old girl, his eyes softening with deep pity, but he remained painfully silent. He knew her body was simply too small, her blood volume far too low to safely donate without putting her own life in severe danger.
Seeing the doctor's heavy silence and reading the answer on his face, the realization hit Mimi all at once. Big, heavy tears spilled over her eyelashes, streaming down her red cheeks.
"Please!" Mimi burst out sobbing, her tiny shoulders shaking uncontrollably as she cried out into the quiet corridor. "Please don't let him die! Take my blood! Save Haruto-niichan!"
Mikasa dropped to her knees, pulling her weeping daughter tightly into her arms, while Akari pressed her back against the wall, watching the last hope shatter into pieces. Time was running out, and they were officially out of options.
Dr. Ken lowered his clipboards, his hand resting heavily on the metallic edge of the counter. The heavy silence in the hospital corridor was broken only by Mimi's quiet, hitching sobs, her face buried deep into Mikasa's trembling shoulder.
Akari leaned her forehead against the cold wall, her fingers digging into the plaster. Every avenue was closed. Every branch of the family line had turned up empty or unfit.
"There is one possibility remaining," Dr. Ken said softly.
The words fell like a sudden weight. Akari's head snapped up, her bloodshot eyes wide. Beside her, Renjiro straightened instantly, his posture rigid, while Mikasa looked up through a veil of tears.
"Who?" Akari whispered, her voice edge-thin. "Dr. Ken, who else is left?"
Dr. Ken looked from Akari to Renjiro, his expression grim, carrying no triumph—only a cold, medical necessity.
"Kaito."
The air in the hallway instantly shifted. The quiet tension turned brittle, freezing everyone in place.
"His brother," Dr. Ken continued, his tone low and steady. "Based on the lineage records and the rare Seiryū markers in Haruto's blood, Kaito is the only individual left whose blood profile matches the required factors. If anyone can donate safely without triggering an immediate immune rejection, it is him."
Dr. Ken paused, looking straight into Akari's eyes. "We are running out of time. Haruto's volume is dropping to critical levels. We cannot keep searching indefinitely. If we don't proceed with a transfusion soon, his system will fail."
The return trip to the Inazuma household felt less like a walk and more like a procession toward an inevitable confrontation. Akari, Renjiro, Mikasa, and Mimi walked together in complete silence, the midday sun offering no warmth against the heavy dread settling in their chests.
When the front door slid open, the house was entirely quiet. The physical wreckage from the previous night had been scrubbed away, but the atmosphere remained thick and suffocating.
Kaito had not left his bedroom.
Renjiro stepped forward, stopping outside the wooden sliding screen of Kaito's room. He didn't knock aggressively; he simply called out, his deep voice resonant and quiet.
"Kaito. Come out into the living room. We need to speak with you."
A long silence followed, broken only by the faint creak of floorboards inside. Slowly, the wooden door slid open. Kaito stepped into the hallway, his face wrapped in fresh bandages, his jaw bruised, and his posture rigid. He looked at the four of them standing in the central room—Akari, Renjiro, Mikasa, and tiny Mimi clinging to her mother's hand.
He didn't speak. He simply stood there, his dark, hollow eyes darting between their serious expressions.
Akari stepped forward, forcing her voice to remain calm, steady, and entirely honest. She didn't offer empty platitudes, nor did she order him.
"Kaito," Akari began softly, keeping her hands clasped tightly in front of her. "We just came back from the hospital. Haruto's condition has taken a dangerous turn. His body lost too much blood from the fight and his internal trauma. His levels are critically low."
Kaito's gaze remained cold, unblinking.
"The hospital's blood bank doesn't have a match," Akari continued, her throat tightening despite her best efforts. "We tried to donate, but our blood isn't compatible. Mikasa-sensei cannot donate due to her condition, and Mimi is too young. Dr. Ken ran the lineage records... you are the only person left whose blood matches his."
She took a slow, painful breath, looking him directly in the eye. "Without a transfusion, Kaito... Haruto may not survive."
She didn't demand. She didn't beg. The truth hung raw and unvarnished in the middle of the room.
Kaito understood instantly. Every detail of what they were asking hit him all at once, stripping away the calm surface and exposing the dark, festering ruin beneath.
A faint, bitter smirk pulled at the edge of Kaito's bruised lip, though his eyes remained dead.
"What's the difference?" Kaito rasped out, his voice sharp and laced with a toxic edge. "I'm just three years older than Mimi."
Mikasa gasped softly, but Kaito didn't look at her. His gaze snapped straight to Akari and Renjiro, his posture tensing as a wave of paranoid, agonizing fury rushed back into his chest.
"You all hate me, right?" Kaito sneered, his tone rising, raw and venomous. "You've looked at me like I'm a monster ever since yesterday! So why do you suddenly need me now? Why am I suddenly so important?!"
"Kaito, that's not true—" Akari tried to step closer, but Kaito took a sharp step backward, pointing his bandaged hand at them.
"Don't come near me!" he spat out, tears of pure rage suddenly welling in his bloodshot eyes. "You don't care about me! You don't want me! You just want my blood!"
He thrashed his arms wildly, his chest heaving as the suffocating grief swallowed him whole.
"You just want me to die so Haruto can live!" Kaito screamed, the accusation shattering the quiet of the house like glass. "That's what this is! Take my blood, drain me dry, get rid of the problem! You all wish it was me instead of him!"
"Kaito, listen to us," Renjiro said, stepping in front of Akari, his voice low and firm. "Nobody wants you to die. We are trying to save both of you."
"Liar!" Kaito sobbed, his voice cracking into a gut-wrenching ruin as he gestured wildly around the restored living room. "When Ayame was alive, you all acted like a family! You smiled, you played along, you pretended everything was fine! Now she's gone, and suddenly I can see what you really are!"
He stared at them with absolute, tragic betrayal, his young mind entirely consumed by the pain of his sister's loss.
"You never cared about us," Kaito whispered, his voice dropping into a hollow, trembling rasp. "You just wanted the quiet little family. And now that it's broken, you just want to use me to fix your favorite one."
Before anyone could utter another word, Kaito turned sharply, bolted into his bedroom, and slammed the heavy wooden door shut with a deafening BANG.
The click of the latch engaging echoed through the hall.
Akari flinched, taking a desperate step toward the closed screen. "Kaito—"
"Akari," Renjiro said quietly, extending an arm to block her path.
She stopped, looking back at him. Renjiro slowly shook his head, his face somber.
"Not right now," Renjiro murmured, his voice heavy with sorrow. "Pushing him through a locked door right now will only shatter what's left. Let him breathe."
Akari stared at the wooden panel for a long, agonizing moment, hearing the faint, ragged gasps of Kaito's quiet weeping from the other side. She slowly let her hand fall back to her side.
Behind them, Mikasa held a crying Mimi close to her chest, while the shadow of the closed door lengthened across the floorboards.
Inside the dark room, Kaito sank to his knees against the wood, pulling his legs tightly into his chest, entirely alone in the dark.