Tanjiro's growth development as a demon slayer is significant because it showcases his determination, resilience, and empathy. Throughout the series, Tanjiro undergoes intense training and faces numerous challenges that test his abilities and moral compass. His growth reflects his unwavering commitment to protect others, his capacity to learn from his mistakes, and his willingness to empathize with both humans and demons. Tanjiro's development also highlights the importance of personal growth, perseverance, and compassion in overcoming adversity and fulfilling one's destiny as a demon slayer.