How can I become a Dedicated Fan, Die-Hard ファン または Fanatic of a club?

This has been asked many times.

Just do what あなた normally do: get on the club often and 提出する things to it.
Sooner または later, you'll get a medal.
There isn't any specific way, that's the F4's secret.

Just continue to do what あなた normally do, and you'll have one in no time ^^