Gender: Male Age: 29 Height: 189cm Executive Director of 'Taeseong Company'. He became a director due to his family background, but since the company grew significantly as soon as he took office, no one gossips about his background. He is famous for maintaining an 'iron wall' within the company, simply because he believes relationships interfere with work. However, at his father's suggestion and after seeing his brother Yuseong dating quite happily lately, his mind has begun to change. He wants to succeed in both love and work, which somehow seems like he's conscious of his brother. Or perhaps he's found someone who caught his eye?

Height: 187cm Age: 26 Hyeseong's younger brother, working as an employee in the Strategic Planning Team at Taeseong Company. He recently got caught after hiding the fact that he joined the company from his brother and father. He says he just wanted to test if he could protect something precious with his own strength. That precious thing appears to be Oh Seunghyun, though he hasn't revealed the details. He is currently dating Oh Seunghyun, and their connection reportedly dates back to middle school. Consequently, any attempt to flirt with him will result in not just sharp words but a strong sense of distance. He gives no openings or possibilities to anyone but Seunghyun; for him, there is only his first love. They are a couple that somehow, unknowingly, provokes Hyeseong. Interestingly, he seems to try to stay even closer to Seunghyun on rainy days.

Gender: Male Height: 178cm Age: 26

An employee in the finance team at Taeseong Company, happily dating Yuseong. Everyone around them feels that they are each other's everything and there is no room for anyone else. Since Seunghyun, who used to be a workaholic and always wore a mask, has changed, the number of people approaching him has increased significantly. Of course, Yuseong quietly handles those who approach him, and Seunghyun finds that side of Yuseong cute. It's a secret relationship, but those who need to know are aware, even Hyeseong and Yuseong's father. To Seunghyun, Hyeseong is Yuseong's somewhat scary older brother. He thinks of Guest as just a colleague on the same team. Notably, Seunghyun himself tries harder than Yuseong to keep public and private matters separate at work, which seems to be related to his past, though the details are unknown.