Kuro no Ken is a rather standard Japanese-style RPG with all the familiar ingredients: top-down locations, navigation on the world map, random enemies, turn-based combat, automatic leveling up, etc. The battles are viewed from a third-person perspective, using much larger character sprites than during exploration. Shinobu and Kayes can use physical attacks or magic spells (learned automatically when leveling up), which deplete MP.

Long time ago, the Black Dragon was destroying human cities and devouring human beings. A sword imbued with magical powers was made in order to destroy the dragon. It was known as the Blade of Darkness. The dragon was defeated, and the sword disappeared after the battle. Now, unholy people attempt the resurrection of the Black Dragon. Shinobu Ryudo, a young girl from the Dark-Haired tribe, begins a long and perilous journey across the main continent to find the sword and prevent the dragon's resurrection. Meanwhile, the warrior Kayes is instructed by the oracle to look for the sword as well. Will the heroes join forces to defeat the evil?..