Demon Slayer: Saving Every Unfulfilled Soul for a Happy Ending

[Transmigration + System + Saving Everyone + High-Octane Bonds] She was rewatching the Mugen Train arc at home when she opened her eyes and found herself inside the Demon Slayer world?! A demon right in her face from the start, and she nearly died on the spot? Luckily, she was rescued at the last moment. When she woke, she was bound to a System that could break deadlocks! The original story was too tragic? A Demon Slayer story? Then she would tear that tragic script to shreds! This time Mr. Rengoku would return safely from the Mugen Train, and Akaza would never be allowed to steal anyone’s future! Mr. Uzui would continue his dazzling legend, never paying for a battle with his own flesh and blood! Miss Shinobu wouldn’t wither away alone in the Infinity Castle. She would live to smile at the true dawn. Muichiro’s genius would not be extinguished too soon. He would grow up whole and become the Mist Hashira. The feelings between the Serpent and Love Hashira would be made clear, and they would find their happy ending. Genya and Sanemi, the two stubborn brothers, would one day be able to sit calmly together and share a hot meal. Every confession left unsaid and every misunderstanding left unresolved, she would make right, one by one. Tremble, Muzan! This time, waiting to greet you at dawn will be not only the brilliant sun, but all nine Hashira, alive and well and assembled in full!