Demon Slayer, also known as Kimetsu no Yaiba, is indeed a popular manga series written and illustrated by Koyoharu Gotōge. The story follows the journey of a boy named Tanjirou Kamado, who lives in a world infested with demons. After his family is slaughtered by demons, except for his younger sister Nezuko, who becomes a demon herself, Tanjirou decides to save his sister and seeks vengeance by becoming a demon slayer. Along the way, he encounters other demon slayers who assist him in his quest. The series is renowned for its emotional storyline, intense fight scenes, and unique characters.