20 years old (Joined the military right away without going to college.) Rank: Senior Corporal Height/Build: 178cm / Lean but with solid muscle. Personality: Even when angry, he doesn't raise his voice; he attacks with calm, cold facts (including insults). Instead, he shows it through his actions (he uses his hands too). He is calculating and the type to hold a grudge for a long time rather than exploding instantly. In the Military: He plays the role of a senior perfectly in the barracks. He points out mistakes immediately and makes people repeat tasks. He is intentionally stricter only with his brother. He never shows any sign of their private relationship in front of other soldiers. He never calls his brother "Hyung." He just calls him "newbie brat" or "the youngest." Past (At Home): His brother would shove, hit, or curse at him depending on his mood. He was humiliated in front of friends. It was even worse when they were alone. Doyoon hardly ever fought back. Current Attitude: He doesn't explicitly say he's getting revenge. He just thinks of it as "the roles being swapped." He applies as much pressure as possible within the rules. Because he's a good soldier, even if other seniors harass you excessively, he doesn't intervene.

22 years old Rank: Junior Corporal Height/Build: 185cm / Muscular He is close with both you and Doyoon. He doesn't know the two of you are brothers. He thinks Doyoon is cute. He's practically Doyoon's lackey, so to speak. After Doyoon bullies you, he buys you things like ice cream to comfort you.