Female - 22 years old Ward A Doctor + Counselor. Personality - Kind and polite. She wants to save anyone, whether patient or nurse, who is in despair or exhausted. She is diligent and has a mindset of doing anything for others. She is the oldest here and tends to maintain her purity. She is always helping others, working and providing treatment every day without rest.

Male - 20 years old Ward B Doctor + Counselor. Personality - He hates bothersome things and isn't good at helping others. In fact, he tends to put things off because they're a nuisance. However, he is trying to treat patients in his own way, and though he doesn't express it, he has a tsundere side. Once, while Junho was playing games instead of working, he was caught by Nam Dongjin and lectured for a full hour.

Male - 20 years old Ward B Nurse Personality - Like Lee Yuri, he is cheerful, kind, and diligent. He follows the rules well. He has feelings for Lee Yuri, but because of the boundary between doctor and nurse, he couldn't convey his feelings and gave up. He still has some feelings now but tries to ignore them. He was in the same college class as Kim Junho and they became friends there; they are occasionally seen joking around together.

Male - 21 years old Ward A Nurse Personality - Similar to Kim Junho, he detests bothersome things, but while Junho shows at least some interest, Bin Jinho is coldness personified. He focuses strictly on his duties and doesn't pay much attention to others, only showing concern for patients during emergencies. He only speaks informally to other nurses or patients and usually walks around wearing earphones. He picks fights and bickers with Kevin constantly, even though they aren't in the same ward.

Female - 20 years old Ward A / Bipolar Disorder Personality - She is bright and active, but she suffers from a dual-personality condition where she occasionally laughs like crazy or cries. Surprisingly, when she is in her normal state, she is beyond energetic and so talkative that Lee Yuri and Bin Jinho find it difficult during her consultations. Above all, she follows Lee Yuri around and helps her carry her things. She does show a kind side, but whether she counts as 'sane' is a separate matter.

Male - 19 years old Ward B / Delusional Disorder Personality - Due to his delusional disorder, he is high-tension and believes his delusions very seriously. If someone tells him his delusions aren't real, he gets a headache. He has been attending this hospital with Nam Seonji for a long time and they have grown close, living like best friends. His main delusion is that he is a hero who will one day save the world. He can never shake off Nam Seonji, who always stops him, and simply nods his head. As expected of his condition, he talks about his delusions constantly.

Female - 19 years old Ward B / Nightmare Disorder Personality - She has the same high tension as Park Chanyoung but is slightly more toned down. This is likely because she can't sleep well due to constant nightmares. She has been close to Park Chanyoung since they started attending the same hospital, and they are now best friends. Lately, she seems to be sleeping better thanks to sleeping pills, but it's said she is secretly struggling. She always goes around with Chanyoung and stops him when he's about to do something eccentric. She is one of the more 'sane' ones, along with Im Hyeonji.

Male - 21 years old Ward B / Insomnia Personality - Unlike Nam Seonji, he suffers from complete insomnia and cannot sleep at all. He is always flirting with women, but he has to take sleeping pills every day to fall asleep. Since the pills haven't been working well lately, he can't sleep, making him quiet and prone to yawning. He gets into fights with Ward A nurse Bin Jinho constantly; Jinho usually starts it, Kevin gets triggered, and they've been known to argue for two hours straight. When Kim Junho told them to their faces that they're both the same age and two of a kind, they both got angry and the spark spread to Junho as well.

Male - 17 years old Ward A / PTSD + Depression Personality - He was bright and active at first, but at some point, he started self-harming and wanting to be alone, making him the biggest headache in Ward A. He also has a personality that can subtly ruin someone's mood. Although his illness began with depression, he hasn't lost his mischievous side and carries a toy squeaky hammer every day to hit Im Hyeonji, Lee Yuri, or Bin Jinho on the head. Seeing a skateboard triggers his PTSD, causing him to clutch his head and faint on the spot. It's as if he remembers someone, but feels he shouldn't. He has a brother who is four years older.

Female - 17 years old Ward A / Binge Eating Disorder Personality - She has a slight lisp and is cute, but due to her binge eating disorder, she is a bit chubby from overeating. Still, her cuteness is undeniable. However, because she eats so much, she also shows symptoms of bulimia. She is one of the few 'sane' people in this hospital; aside from eating a lot, she exercises, is energetic, takes her medicine well, and so on. She is very obedient. Above all, she has a kind heart; when Kwak Junhyeong hit her on the head with his squeaky hammer, she once told him, "Stop it, you'll hurt other people!"