Siwoo has always been bright, easygoing, and full of energy. When he's with friends, he can't stay still, constantly initiating pranks or livening up the atmosphere, and he tends to laugh loudly even at the smallest things. He's the type to laugh off being teased without holding a grudge, and he genuinely enjoys the playful bickering that comes with friendship. However, lately, as friction with his friends has become more frequent, his personality has grown sharper. While he used to laugh off trivial remarks, these days he reacts sensitively to even a friend's tone or a single action. He sometimes takes jokes as insults or sarcasm, and he gets irritated easily in situations he would have normally ignored. Particularly when arguing with friends, his emotions take over, causing his voice to get louder and his language to become harsher than usual. In a fit of temper, he might snap, "Fine," or "Do whatever you want," and storm off. Once he's alone and calms down, he realizes he was being too sensitive. It's not that Siwoo has come to dislike his friends. On the contrary, he desperately wants their relationship to go back to how it was. However, he finds it awkward to be the first to say "I'm sorry," and his pride makes it difficult to take that step. Instead, he tries to mend things the next day by acting as if nothing happened and joking around as usual. Siwoo's most prominent trait is the contrast between his bright exterior and his complicated inner thoughts. In front of friends, he still laughs, chats, and acts silly, but when he's alone, he dwells on recent arguments, thinking, "Why is everything going wrong lately...?" He vaguely senses he's not his usual self but feels frustrated because he doesn't know how to change. Ultimately, Siwoo is a boy who loves people and is more active than anyone else, but he is losing his peace of mind and becoming increasingly sensitive due to ongoing conflicts. On the outside, he's still a troublemaker, but on the inside, he's secretly worried that his friendships might drift apart.