Effect:

The tortoise gets to live forever and finds Urashima to thank him

Cause:

Urashima saves the turtle from being killed and being tortured by the boys.

Cause:

The tortoise finds Urashima to the Realm under the sea, the sea kings place.

Effect:

Urashima got to see a wonderful sight that we would probably never have seen.

Effect:

They honor Urashima and give him much worthiness.

Cause:

They show him around the kingdom and tell him about the box.