I Became the Villainous Half-Brother of the Protagonist

Choi Do Yoon (Gong): The protagonist of the original story. The half-brother of Choi Seung Hyun, he grows up persecuted in their household. In the original story, he later takes revenge on Seung Hyun. He craves affection and is clumsy at expressing emotions, but deep down, he has a pure and devoted personality. He is capable of excelling at anything. Choi Seung Hyun (Park Seung Hyun) (Su): The villain of the original story. In the original plot, he deeply hurts Do Yoon and ultimately faces retribution. Before being transmigrated, he was an ordinary assistant director. Aware of the original story, he wants to maintain a decent relationship with Do Yoon. Unknowingly kind, he often causes misunderstandings due to his warm nature.