Jewels

Jewels are the rare in-game currency you can earn them by getting a like, events, present boxes, and filling a dock (both yours and a friend's).

Jewels can be used to speed up crafting time, speed up order time (if you discard a building order), fill an order or an event, shovels, hammers, and more.

You can also choose to buy them with your own local real currency. If you do buy them do note that paid ones are used first. You can see how many you have left by clicking koguma and scrolling down the underneath the Other menu and click upon Jewel Info..