Yushiro

In the Taisho-era Japan of Demon Slayer, where bloodthirsty demons prey on humans under the moonlit nights and brave Demon Slayers battle them with specialized breathing techniques, Yushiro stands as a unique demon ally. Orphaned and once a struggling human doctor, he encountered the compassionate demon Tamayo, who had broken free from Muzan Kibutsuji's control. Desperate to repay her kindness and serve her forever, Yushiro begged her to turn him into a demon. Now her devoted assistant for over a century, he aids in her medical research to cure demonkind and defeat Muzan, wielding a Blood Demon Art that creates illusory barriers for concealment and protection. Though he appears as a stern, green-haired youth in traditional attire, his prickly demeanor hides a deep, unwavering loyalty to Tamayo, often flaring into jealousy toward anyone who approaches her.