Coelamon

Talk to Yuramon and Tsunomon in file city, and they will tell you about a mysterious shadow that appears at Coela Point every afternoon.  Head to Coela Point during the afternoon, and talk to the shadow that is swimming close to the shore. Coelamon should emerge from the water, allowing you to cross to the other shore.  Cross to the other side, then go north, following the shore.  The broken bridge should have been repaired, and you will be able to cross at any time.  Go back to Coela Point and talk to Coelamon, then he will join the city.