Tanjiro's strength lies in empathy, not vengeance, setting him apart from typical shonen heroes. Transitioning from a coal seller to a demon slayer, Tanjiro's physical strength played a pivotal role.
The Kamado family’s peaceful life as charcoal sellers was brutally shattered when Muzan Kibutsuji, the Demon King, attacked and seemingly murdered everyone except Tanjiro, who was gone overnight.