Tanjiro's resilience and determination play a crucial role in his demon-slaying journey in the anime "Demon Slayer." His unwavering determination drives him to keep pushing forward even in the face of overwhelming odds and challenges. His resilience allows him to bounce back from defeats and setbacks, constantly improving his skills and adapting to different situations. Overall, Tanjiro's resilience and determination not only fuel his demon-slaying abilities but also inspire those around him to do their best and never give up.