At the start of your game you will have some bait, a fishing pole (either Bamboo or Carbon), and a bobber. Using your equipment to catch fish is pretty simple.
Bait Fishing requires you to have a pole, bobber, and bait. You only have to select the 3 items and then you're ready to go! To use bait, stand near the water and activate the fishing mode (R1 on your controller). Then press and hold the X button to cast your line. The longer you hold down the X button, the further your cast will go.
Your basic Bamboo and Carbon Rods don't have a reel attached to them so there isn't a way for you to drag your chosen bait back through the water. Once you purchase the Hera Rod you can reel in your line by pressing the X button.
There are also 4 different bobbers you can select, but the choice of bobber does not affect the fish you can catch. The bobber styles are just for aesthetic purposes so pick the one you like best.
Fly Fishing is a little trickier to work with, but you don't have to put new bait on your hook every time you catch a fish. After you buy a Fly Rod and Flies at the Bait Shop and equip the combination, go to the water's edge and press the X button. Your character will then start whipping the fishing line around his (or her) head.
At this point you can control the length of your cast by pressing the Left Analog Stick. If you hold the analog stick away from you, the line will cast further out. If you hold the stick in the opposite direction the line won't cast out as far and it will land closer to your feet. Release the X button when you have decided how far the line should cast.
Lure Fishing is a combination of the recyclable bait from Fly Fishing and the simplicity of Bait Fishing. You can attach one of several Lures to your Lure Rod and then cast out the line as though you were Bait Fishing. The cast can be reeled back to you just by pressing the X button.
When the fish bites your Lure you won't have it completely hooked on your line. You will have to entice the fish to snag your Lure when you are in the underwater scene. Tap the X button to jiggle your Lure around in the water. If the fish swims close and bites it, then you can reel it in just like the other 2 fishing styles.
The variety of Lures available will respond differently underwater. The Vibration Lure quickly stutters up and down when going through the water, the Bass Bait rotates in a circle, and the Jig just cuts through the water in a straight line.