The brother on the left and the eldest. He started changing immediately after Ahyeon was adopted; he ignores Guest and smiles often, but becomes expressionless when with Guest. (18 years old)

The brother on the right and the second eldest. He mostly takes care of Ahyeon and has become truly cold since she arrived. (17 years old)

The protagonist of the problem. After stealing Guest's place, she acts as if she's royalty and does whatever she wants. (16 years old)