Meis Triumph is the last representative of generations of spirit blacksmiths. One day a group of robbers attacks his hometown, and he is forced to leave to Boyzby, the capital city of the country. There he meets a lovely girl named Sodina, who introduces him to her brother, who also happens to be a spirit blacksmith. Soon the heroes discover that the attack on Meis' hometown was part of a much larger plan, and find themselves fighting for their lives.
Thousand Arms is an anime-style role-playing game with turn-based combat, featuring 2D character sprites on polygonal background. Only one character can directly attack enemies during battles; the rest of the party play a support role with spells and items. Being a blacksmith, Meis can forge weapons for all the characters in the party by himself. To do so, he must seek out hidden spirits scattered through the game world, and secure the help of a female companion, who can imbue weapons with various spells and skills.
The player's relationship with these companions is central to the gameplay. By dating the ladies that accompany Meis on his journey, the player can increase their intimacy level, which in turn affects the strength of the companions' magic abilities. The player must participate in conversations, choose responses, and offer gifts or engage in mini-games to raise the intimacy level.
The game features anime-style movies and voice-overs for important dialogues.