How do you get a Super Rod In Pokemon Diamond?

Question

Where do you go?????

Answer 1

It is route 225

watch this video

http://yotube.com/watch?v=M-81_89hGdI

Answer 2

After you beat the Elite 4 and get the National Pokedex, do to route 225 and there's a fisherman. He's going to ask you a question, so just answer yes nd he'll give it to you. But I don't remember the question.

Answer 3

Once you beat the elite four and complete the sinnoh leage pokedex then when you go to the battle area then you will see a fisher men talk to him and then he will give a super rod.