Koto is a sound plugin developed by Rev Soft Inc for Perfect Piano and Walk Band apps. It is a free multimedia program that allows users to enjoy the traditional Japanese stringed instrument, Koto, on their mobile devices. However, it cannot be used alone and requires Perfect Piano or Walk Band to function.

To use Koto, users need to enter the Keyboard Screen on either Perfect Piano or Walk Band, select the switch instrument icon, and Koto's icon will automatically appear. Users can then load the new sound and enjoy playing the Koto.

It is recommended to adjust the sustain time through the app settings to make the sound more comfortable. If you encounter any issues, you can contact Rev Soft Inc (also known as Revontulet Soft Inc, Revontulet Studio) at

Overall, Koto is a great addition to Perfect Piano and Walk Band for users who enjoy playing traditional Japanese instruments.