Shadow Skill takes place in the warrior kingdom of Kuruda, where the main character Elle Regu has recently become the 59th Sevaar, a title awarded to their most elite warriors. She often leaves a trail of destruction when she fights and along with a drinking habit, Elle is constantly followed by debts. Elle travels along with her adopted younger brother Gau Ban, who is studying Elle's fighting skills so that one day he could become the greatest Sevaar in Kuruda. Also in Elle and Gau's life is Faurink Maya (Faury), a Sui Rame talisman sorceress, and Kyuo Lyu, a Septia beast-catcher and grandniece of Eva Stroll, the king of Kuruda.
Warriors in Kuruda fight using the Kuruda-style Kōsappō (交殺法, lit. "combining kill methods", ADV "Annihilation techniques") which has two general divisions: Hyōgi (表技, "open skills" or "bright skills"), which emphasize punches and throws, and Eigi (影技, "shadow skills"), which focus on kicks and the user's footwork.
