These are youkai who dwell in the river near Youkai Mountain.

They are technologically-gifted youkai that produce various tools with skillful hands.

Similar to the tengu, they have built their own society, more advanced than us humans.

Their appearance is human, but they have turtle shells covering their backs, and plates covering their heads.

Swimming is their forte, and in the water they can move faster than a fish, but on dry land there is no major difference in abilities compared to a human's.

Their fighting skills are also comparatively low, so they seldom show themselves to humans.

Furthermore, since they run away when they notice humans, their way of life is shrouded in mystery.

When they are spotted, it is just the occasional foolish kappa that has been washed down the river.

The tools created by the kappa and the tools of the outer world are treasured as the two greatest varieties in Gensokyo today.

However, it is unknown how to use most of the tools.

The photographing devices used by the tengu are a good example of this.

Even when the button is pressed, it remains silent for some reason.

Others are the clock that somehow tells time correctly, and a device capable of talking to people over great distances.

The mountain society is said to have become very advanced with these various devices, (*1) including ones for transmitting images to other places, as well as receiving them.

1: It is also said that they are created by copying the devices from the outside world, but their waterproofing is outstanding.

Swimming may be the kappa's strong point, but it is not as if they actually live in the water.

Usually they live on land, where they also make their tools.

If an enemy approaches they dive into the water and hide.

However, while they can stay under water longer than a human, they cannot remain there forever. They must surface for air eventually(*2).

Kappa clothing is very water-resistant, so is possible to wear it into the water, and it won't interfere while swimming.

2: They can hold their breath for several hours.