Tanjiro felt discouraged, but was determined and encouraged by his desire to save Nezuko. After two full years of training under his first teacher, Sakonji Urokodaki, Tanjiro cleaved the boulder ...
Considering how strong Nezuko became as a demon and how strong Tanjiro grew as a swordsman, it's possible that his younger siblings could have also risen to the ranks of the Twelve Kizuki, adding ...