Demon Slayer: I Am Muzan's Mentor

【Sweet romance + heroine who grows over time】 The orphan Sakuya suffers a sudden, devastating loss when her parents are killed by demons. Lost and alone, she meets the reclusive Rokusha Sakuji, who comes to her aid and takes her to his home deep in the mountains. Sakuji was a former Hashira of the Demon Slayer Corps, and his wife, Yozuki, is kind and gentle, treating Sakuya like family. Seeing Sakuya’s resilience and her unwavering spirit despite all she has suffered, Sakuji decides to teach her. He tells her he has mastered the secret art of “Dusk Breathing” and offers to make her his first disciple. Grateful for being saved and determined to protect the people, Sakuya accepts his offer. For five years, Sakuya studies under her strict master and receives a mother’s loving care as she trains hard in “Dusk Breathing” beneath the moonlight. Her body grows stronger, and she begins to master the sword. On her fifteenth birthday, wearing a haori and hair tie made from her parents’ belongings and carrying the Nichirin Blade Sakuji gave her, she heads to Mount Fujikasane for the Final Selection. Wisteria blossoms fill the mountain, and demons lurk everywhere. She only hopes to survive the seven-day trial. But a sudden upheaval takes place in the mountain, and she witnesses Giyu pleading through tears. With the situation so dire, how can she stand by? Though she knows fate cannot be changed, she cannot bear the thought of a loved one dying. At last, Sakuya abandons her plan to live in seclusion and rushes into danger with her sword. There she finds a monstrous demon displaying terrifying power, while the heroes of old hang by a thread. At that moment, a deep blue flash of swordlight bursts forth, like moonlight flowing across the night sky “Dusk Breathing” makes its first appearance in the world. A single act of compassion from a young girl may change what seemed set in stone. With this blade drawn, the road ahead is fraught with uncertainty. She can only think of the humble mountain home, her parents waiting at the door, and pray she can overcome this calamity and return beneath the moonlight. Thus begins the tale: An orphan, saved and raised in the mountains, masters a secret art and tests her blade; the winds of change sweep through Mount Fujikasane, and one stroke may turn the tide of fate.