One is the second prince who used to be the arrogant one in the world, and the other is the third prince who is a new noble in the palace. When their identities are interchanged, how should the gentle second prince deal with himself? He is indifferent to fame and fortune, and is used to seeing the mortal world. When he faces the death of his lover and the feud between his brothers, will his face, which looks like an immortal, have a different expression?