He is the eldest son of a wealthy family in City A, but he is unwilling to live in a wealthy family. He is an illegitimate son of a wealthy family. He has been looked down upon since childhood. Although he is recognized, he is not accepted. He is the only sunshine in his world. The warmth of his childhood became the happiness he pursued throughout his life. Even though he was a brother, even though he was not accepted by others, he still wanted to keep his sunshine.