How do you use this stone?

Go to YouTube 'Okatsune Sharpening Stone video" and you will find a demonstration of how to use the stone.

Are there instructions with this stone on how to use it?

Great question with a hilarious answer. The instructions are one page written in Japanese! There are some pictures that help give you an idea as to how to use the stone. But other than the pictures you are out of luck. With that said I do not regret purchasing my stone and use it quite often to sharpen my outdoor tools. It brings a dull edge back to sharpness in no time.

Is this stone what I sharpen the pruner 103 with?

This stone can be used to sharpen Pruner 103.

Can someone please translate the instructions? Does it say to wet the stone?

ALWAYS wet a stone of this type thoroughly before using. Wetting the stone disperses the swarf caused by the sharpening. It also prevents clogging of the pores on the stone. Clogged stones have very reduced sharpening ability.