Demon Slayer features the evolving relationship between Tanjiro Kamado and Kyojuro Rengoku, highlighting a deep connection forged in the heat of battle. Tanjiro, a young demon slayer, meets Rengoku, the spirited Flame Hashira, during the Mugen Train arc. Initially, Rengoku’s vibrant personality and unwavering dedication to protecting humanity deeply impress Tanjiro, who sees in him the qualities of a true warrior and mentor.
As they fight side by side against a formidable demon, Rengoku’s strength, courage, and relentless will inspire Tanjiro, who yearns to emulate his valor. Rengoku, in turn, recognizes Tanjiro’s potential, empathy, and resolve, treating him like a younger brother and passing on vital lessons about resilience and the flame of hope. Their bond exemplifies the mentor-student dynamic, leaving a lasting impact on Tanjiro as he continues his journey, carrying forward Rengoku's fiery spirit and ideals.