To make a good fishing rod, you’ll need a thread. You’ll need it for repairs. We’ll tell you how to get it below.
Unfortunately, the main character’s home island does not have enough strings to complete the mission. A little thread can be found inside the box on a broken beach boat. But anyway, you’re gonna have to jump in a boat and go to Calis.
When you get to the mainland, you get an assignment to meet the old lady from the lighthouse, Koa. Go to the lighthouse and have a chat with her. Go back to the dock and talk to Noho. He’ll tell you a story, and then demand a product in exchange for information. So you’ll learn the recipe for the threads. You will also be given cotton seeds. Make sure you put him on your island!
When the cotton grows, pick it up and then use the workshop inside the house to create a thread. To complete Noho’s quest, you’ll have to collect two reels of thread.