Alternative: Although a koma is required for a standard shamisen setup, practically speaking, the koma is simply a bridge to carry the string vibrations to the skin. If you can’t afford a koma or want an effective substitute, you can easily replace it with a shortened pencil or a chopstick to make your shamisen playable.
The tone won’t be as good as a professionally made koma, but it will allow the shamisen to produce sound. Often, if I need to study a short phrase on shamisen for a few minutes, I’ll just slide in a pencil because I don’t need it to sound perfect, just good enough for quick practice.
