Wow I must say I'm amazed! They give Ring Ding Dong a new style very different from SHINee's - but still very good.
The brother-sister duo are K-pop star 2 contestants who make Korea fall in love with them. Their recent release of "I Love You" for 'All About Romance' OST (http://www.vingle.net/posts/132853) beats Psy's Gentleman to claim #1 on music chart!
What's even more surprising, Lee Chan Hyeok (the brother) was born in 96 and Lee Soo Hyun (sister) in 99.