In a far away land stated two kingdom that was built around 200 years ago. Distance between two kingdom was not too far yet not to close. One day the king from both kingdom decides to unite and have a good relationship. By doing that they decides to have an arrange marriage between their children. 

First Kingdom: King Choi Lee 

The king and his wife gave birth to two courages sons: Siwon (oldest.23) and Leeteuk (youngest.20)

Siwon: Very brave.  Good sword's man. Always protect ONLY his baby brother from harm. 

Leeteuk: Talented in music. Knows how to play various kind of music instrument. warm hearted. 

Second Kingdom: King Han Kim 

The king and his wife gave birth to two lion-heateredness sons:Hankyung (oldest.23) and Heechul (youngest.19) 

Hankyung: Artistic. Knows drawing and very excellent in dancing. 

Heechul: only thinks of himself. clever. bold. cold heated. (i think that summon up everything!) 

While Siwon and Hankyung was still 7 years old they were set to meet up with each other. However they hardly like each other. They love fighting with each other. 

As for  Leeteuk and Heechul - well they meet each other on their brother's 50th meet up day (that is when they are 16 years old).  They got closer each day.