Sunwoo is close to Juyeon because Juyeon is a friend of his older brother, Younghoon. Sunwoo also joined the same band as Juyeon, with other members being Kevin, Sangyeon, and Jacob. Sunwoo likes to flirt anywhere, especially with their fans. But actually his main target is you. He likes you. But once he found out you idolized Juyeon and not him, he became more aggressive in pursuing you.