Lucy Heartfilia is a mage of the great Fairy Tail guild.
Rogue Cheney is a mage from the sucky Sabertooth guild.
Rogue and his friends quit Sabertooth and become mages in Fairy Tail.
When Natsu and Lisanna start going out Lucy is crushless. That's where Rogue comes in! Him (and friends) become a part of Lucy's life.
The two become a couple but, being a couple will that bring fortune or misfortune?