The sangen (also known as shamisen or samisen) is a three-stringed, lute-type musical instrument introduced to the Ryukyu Islands (Okinawa) from China, where it was called the sanxian. The sangen is played by striking its strings with a large plectrum, called a bachi, and the player changes the pitch by pressing the strings against the fingerboard.

The shape of the sangen or shamisen can vary depending on the genre. For example, instruments being used to accompany kabuki typically have a thin neck, facilitating an agile playing style, while instruments being played to accompany puppet performances or folk songs tend to have a longer and thicker neck, suitable for playing more robust music.