After being brutally beaten by Kibutsuji Muzan, Yosuke hid away in his room, training day after day, unaware that outside the world was already in turmoil—many people had gathered, intent on taking his life.
Yosuke laid out a long-term strategy for the future, which could be summed up in a single word: endure.
He firmly believed that as long as he endured and kept developing, with the system in his hands, the day would come when he could grind that wretched boss beneath his feet.
For now, his sole objective was growth—over and over again. Unless he became invincible, his plan was to wait until Yorichi Tsugikuni was born, then team up with the strongest warrior this world would ever see and drag that despicable Muzan straight to hell.
And if that failed, there was still Kamado Tanjiro, that iron-headed boy, as a backup. Solid.
There was no way Yosuke would go challenge Muzan now. If that scumbag suddenly decided, "There is no need for two Demon Kings in this world," Yosuke was certain he wouldn't survive.
No—clinging to survival was the only true path.
Having fixed his direction, Yosuke lay on his bed, staring up at the moon through the window, unable to sleep.
As a demon, he felt no drowsiness at night—his mind was sharp, his body brimming with energy. Instead, he found himself dozing during the day; his entire body clock had flipped upside down.
Just as his thoughts drifted, his sharp hearing picked up footsteps outside.
Because of him and Muzan, the surrounding residences had long since been abandoned. The other members of the Ubuyashiki clan had left the estate.
Now, only Yosuke and his mother, Ubuyashiki Mikako, lived here.
Yosuke rose and opened the door. His keen eyesight quickly spotted his mother in the distance, hobbling toward him on a cane, her steps unsteady.
In the blink of an eye, Yosuke was at her side, holding her up.
"Mother, your body hasn't recovered yet. How could you get out of bed? You need to rest." His voice was filled with pain for her.
He felt his parents had been far too tragic. They were good, kind people who had once looked toward the future with hope. Yet from the very start, both of their sons had been plagued with illness. And when that illness was finally cured, the two of them became demons instead. Their lives had swung from comedy to tragedy in a heartbeat.
Mikako was only thirty, yet she looked past fifty—if one were being generous. Her temples were white, her cheeks sunken, heavy dark circles under her eyes. Yosuke's heart ached just to look at her.
"Yosuke… don't stay here any longer. A group has gathered outside, planning to kill you at dawn. Leave, my son." Her eyes were full of guilt as she looked at him.
"Then let's go together, Mother. We'll find a place where no one lives, and we'll make a life for ourselves."
Right now, Mikako was his only attachment.
But Mikako only shook her head with a faint smile. "I won't go with you, Yosuke. I don't have much time left."
"Mother, if you drink my blood, you'll live forever. Illness will be no problem!" Yosuke was already raising a claw to his palm, ready to cut it open and feed her his blood.
But Mikako stopped him. Though her hands were frail, Yosuke felt a crushing weight, as if she were holding him down with all the strength in the world.
"Yosuke, I don't want immortality. Your father is waiting for me—we vowed to walk together, and as his wife I cannot abandon him. Forgive me for being selfish, Yosuke."
Yosuke bit down on his lip and said nothing.
Mikako released his hand and gently stroked his face.
"I wish I could see you grow up, get married, have children. I wonder what kind of woman your wife will be—surely someone gentle and kind. Yosuke, I'm sorry I can't stay with you any longer. I've failed you as a mother.
Eternal life only brings endless loneliness. Yosuke, you must hold onto your heart. Don't lose your humanity like your brother. At your core, you are still human."
Her voice grew weaker and weaker. Yosuke pulled her into his arms. As a demon, he could already sense it—her life was coming to an end.
"Yosuke, promise me… you must stop your brother. We brought demons into this world. That means we are responsible for eradicating them. It is our burden, our sin."
"Mother…"
He wanted her to stop speaking, but she only shook her head faintly.
"Promise me, Yosuke… please?"
His eyes brimmed with tears, but he refused to let them fall. He couldn't let his mother see him weak.
"…I promise, Mother. I will destroy the demons."
Mikako smiled and stroked his hair, just as she had when he lay sick in bed as a child—so tender, so gentle.
Her gaze lifted past Yosuke's shoulder, her eyes suddenly glowing with light.
"Takuto… have you come for me?"
In her vision, her husband, Ubuyashiki Takuto, stood behind Yosuke, smiling warmly down at her. His presence was as soft and comforting as ever.
"Mikako, I've come to take you."
Tears streamed from Mikako's eyes. "Takuto, my heart aches. We've left this burden on Yosuke. Was that truly right?"
Takuto wrapped her in his arms. "Mikako, Yosuke is our son—our pride. We'll watch over him from above, blessing him always. We should believe in him, shouldn't we?"
Resting in his embrace, Mikako smiled at Yosuke. "Yes… Yosuke is our pride. I will always believe in him."
"Mikako, let's go."
Hand in hand, their figures slowly faded away.
Yosuke sat frozen, staring at his mother's lifeless body in his arms—her face peaceful, still carrying that final, blissful smile. His heart felt hollow.
At last, his tears spilled over. But he wasn't sorrowful. Deep down, he believed his mother and father were now together in heaven, living happily.