Demon Slayer -Kimetsu no Yaiba- The Movie: Mugen Train

Storyline

Following their rehabilitation training, Tanjiro Kamado, Zenitsu Agatsuma, and Inosuke Hashibira embark on a new mission aboard the Mugen Train to investigate the disappearance of over forty passengers and aid the Flame Hashira, Kyojuro Rengoku, in his ongoing hunt for a demon. Upon boarding, they quickly encounter Rengoku, who is already engaged in battle with a demon. After the initial encounter, the group, along with Rengoku, realizes they have all fallen into a deep sleep induced by the Lower Rank One demon, Enmu, who has merged with the train itself. Enmu uses human agents, who are terminally ill and promised a peaceful end if they succeed, to destroy the spiritual cores of the Demon Slayers, rendering them defenseless. Within their dreams, Tanjiro finds himself reunited with his deceased family, Zenitsu is in a whimsical world with Nezuko, Inosuke leads a party of adventurers, and Rengoku revisits a past memory concerning his father and brother. Tanjiro eventually realizes he is dreaming and, guided by his father's words, commits suicide within the dream to wake himself up. He then helps the others to awaken, though Inosuke is the first to follow his lead. As they fight back against Enmu, who has manipulated their dreams and now seeks to kill them in the real world, the Demon Slayers work together. Tanjiro and Inosuke locate Enmu's neck, which is revealed to be the train's smokestack, and manage to sever it, leading to the train's derailment. However, immediately after Enmu's defeat, the Upper Rank Three demon, Akaza, appears. Akaza challenges Rengoku to become a demon, praising his strength and fighting spirit, but Rengoku steadfastly refuses, upholding his duty as a human Demon Slayer. A brutal and intense battle ensues between Rengoku and Akaza, with Rengoku pushing himself to his absolute limits despite sustaining severe injuries. During the fight, Tanjiro, Zenitsu, and Inosuke, still recovering and injured from the Enmu fight, try to assist, but they are largely outmatched by Akaza's speed and power. As dawn approaches, Akaza attempts to flee, but Rengoku grabs hold of him, attempting to hold him until the sun's rays can destroy him. Akaza tears off his own arm to escape into the forest, leaving Rengoku mortally wounded. Before succumbing to his injuries, Rengoku imparts words of encouragement to Tanjiro, reminding him of his responsibility to continue his family's legacy and to believe in himself and his friends. His death profoundly impacts Tanjiro and his comrades, fueling their resolve to grow stronger and uphold the ideals of the Demon Slayer Corps.