Lee Sungmin - the most richest tycoon of his generation started off with inventing things until he made it big. He had a successful career, a loving and beautiful wife and the most supportive, and dependable best friend.

People loved him, he wasn't conceited and had always been down to earth even though he has 'reached the heavens' with his current status. He was charming and bright until a certain accident killed his wife.

...

Kyuhyun had always somehow envied his older sister. He comes second to her, he didn't really care at first until they both like the same person. And again, even though he didn't like it, he was still no.2.

With the death of Sungmin's wife where does that lead them?