Hyuk was born as a normal kid just like the other kid but no longer after he was diagnosed with a mental retardation due to high fever when he was 4 years old.Due to his condition,he provided with a fully supervision from his parent.He got all the love from a people around him so that he doesn't feel left out eventhought he's different.But he doesn't get an attention from his beloved hyung,Cha Hakyeon who's hate him

Meanwhile,Hakyeon was a stubborn high school boy.Hyuk's step brother.Doesn't get a love from his appa as his eomma had dead.