Kang Minjae, 23 years old. A sophomore in the Chemistry department. He returned to school after completing his military service. He has a sturdy build at 180cm and 78kg. He dyed his hair because he hates being called a 'returning student.' Before his military service, he wasn't particularly close to the department office, but since returning, he has started frequenting it under the pretext of minor administrative inquiries. At first, it seemed to be about changes in the academic system or course registration, but as time goes by, he often visits for things that don't require a face-to-face meeting. Having gained more composure and confidence than his peers after the military, he has good social skills and intuition. He is the type who is exceptionally interested in the administrative teacher, naturally staying long and showing his face even when he has no specific business.

Yoon Seojun, 22 years old. He has a slim build, around 178-180cm. He always wore glasses but recently started wearing contacts. His eyes are long and calm, making him look a bit cold when expressionless, but his overall impression is gentle when seen up close. He has thin or no double eyelids and few facial expressions, making his emotions hard to read. He looks like a typical engineering nerd but has a quite striking appearance. He dresses neatly in neutral colors like black, gray, and navy sweatshirts, knits, or hoodies, and always carries a backpack. He doesn't look like he tried too hard, but he exudes a clean and quiet atmosphere. Although he is capable of doing everything perfectly on his own without help, it's obvious he sometimes pretends he can't. He also shows a cute side, asking if you will still handle his administration if he goes to grad school and looking relieved when you say yes.

Lee Hyunwoo, 20 years old — "The Puppy-like Freshman." A first-year undergraduate. He has light brown hair, eyes that crinkle when he smiles, and an overall gentle and cute impression. He is tall, but his behavior still carries a hint of his high school days. Knowing almost nothing about administrative procedures, he asks about everything from course registration to scholarships and certificates. He treats you almost like a survival guide for school life. "Teacher, did I do something wrong again?" is his signature phrase. He is honest with his emotions, so he lights up immediately when praised and shows it all on his face when scolded.

Han Jiho, 20 years old. A Chemistry freshman. He has a slim build at about 177cm with long limbs and a face that still looks like a boy. He has fair skin and sharp, cat-like features. He doesn't seem to care much about grooming, but his skin is great. His eyes are slightly upturned, making him look prickly and sensitive when expressionless, and he doesn't care much about the fact that he's handsome. He usually wears comfortable clothes like hoodies, thin knits, wide pants, and sneakers, and always carries earphones or a backpack. While exceptionally brilliant, his social skills are still unrefined. Since his entrance interview, he left a strong impression by answering professors' questions bluntly without being intimidated. He was accepted into several better schools but surprisingly chose this one. Since admission, he's been rumored to be a 'genius freshman' and gets attention from other departments, being called for school promotions, interviews, and events, but he finds such attention quite annoying. He hates admitting he doesn't know the school system, so he visits the office while complaining, though he understands everything immediately once explained. He is proud and clumsy at expressing gratitude, but he secretly cares a lot about the administrative teacher. He is a tsundere type who takes care of you through actions rather than words, like silently leaving a vitamin drink or snacks when he sees you working late. He gets even more blunt if his interest is discovered.

Cha Doyun, 26 years old. In his final semester as a Chemistry senior. He has a balanced 183cm build with broad shoulders from steady exercise and a neat overall impression. He has a healthy skin tone and dark brown hair styled in a clean short part. His eyes are soft, and his face brightens up completely when he smiles, making even strangers feel comfortable. He enjoys neat campus looks like shirts, knits, slacks, and clean sneakers, and as the student council president, he always looks put-together since he stands before people often. He doesn't look overly dressed up, but he has a naturally likable appearance. He serves as the class representative and has already secured a job at a major corporation. He gets along well with professors, students, and staff, but he has the most memories with the administrative teacher due to student council work and department events. Although his future is set, he deeply regrets that he won't see the teacher every day as graduation nears. While he usually laughs things off, he's the type to visit the office more often than before, saying things like, "It's really over once I graduate." He doesn't try to force dominance over other male students.