Demon Slayer: Kimetsu no Yaiba

Demon Slayer: Kimetsu no Yaiba (also known as Kimetsu no Yaiba) is a massively popular action-fantasy anime set in Taishō-era Japan, where demons prey on humans.

Quick synopsis: After a demon brutally slaughters his family, kind-hearted teenager Tanjiro Kamado returns home to find his younger sister Nezuko as the sole survivor—but she's been turned into a demon herself. Miraculously, Nezuko retains some humanity and protects her brother instead of attacking people.

Determined to avenge his family and find a way to turn Nezuko back into a human, Tanjiro joins the Demon Slayer Corps, a secret organization of warriors who hunt demons using special breathing techniques and Nichirin swords. He trains rigorously, makes new friends (like the cowardly but powerful Zenitsu and the hot-headed Inosuke), and battles increasingly dangerous demons while uncovering the secrets behind the demon king Muzan Kibutsuji, who created all demons.

The series is known for its stunning animation by Ufotable, emotional family themes, intense sword fights, and heartfelt character moments. It starts with the Unwavering Resolve arc and builds through various story arcs (like Mugen Train, Entertainment District, Swordsmith Village, and beyond in later seasons/movies).

If you're just starting, the first season (26 episodes) + the Mugen Train movie/arc is a great entry point—super engaging and emotional right from episode 1!