ngsatra

Ranger HQ on Kakori Island has a lady sitting on the sofa right of the entrance who will teach signal beam for 3 green shards.

Seems so? The one I got was also shiny.

You get it as a reward for completing the Kimono Sisters sidequest and challenge (start at Rose Theater).

Where on earth can I find a hard stone. I swear I've searched everywhere.

Game stuck here on a cut scene, I found that if you come off the bridge and move one square down before the cut scene, you become stuck like this.