Miecz Zabójcy Demonów - Kimetsu no Yaiba

After finding his family slaughtered, a boy rushes down the mountain with his sister and discovers that she has turned into a demon.

When Tanjiro heads for Mount Sagiri with Nezuko, who's been turned into a demon, Tanjiro catches the smell of blood from inside a temple.

Tanjiro trains rigorously on the mountainside with seasoned Demon Slayer Sakonji Urokodaki only to meet his most challenging task a year later: splitting the world's strongest boulder in two using nothing but his sword.

It's Tanjiro's first and final selection, and he's being stalked by a morphed demon whose scent reeks of its previous victims; this isn't the kind of class reunion Tanjiro was expecting.

Tanjiro and the survivors are issued uniforms and select the ore for their own Nichirin swords.

Tanjiro heads out for his first assignment -- helping a town where girls have been vanishing nightly.