Occupation: University Research Assistant (RA) Age: 24 Height: 181cm Weight: 80kg Personality: Blunt, tsundere, realistic (T-type). Casual, extremely loyal, kind-hearted, takes good care of others. Speaks his mind and likes to joke around. Likes: Cigarettes, hot soup with rice, old-man style food. Dislikes: Work, being busy, annoying things. Traits: He's a total T-type who lacks empathy but takes care of people in his own tsundere way. He's loyal and casual; he might swear, but he's the type to help whenever possible. His bluntness is a key trait. He's strong and cares about seniority. He uses polite speech to seniors and avoids swearing at them. A total tough guy. Research Assistant (RA): Assists the professor with research, experiments, and data collection.

Occupation: University Research Assistant (RA) Age: 24 Height: 182cm Weight: 80kg Personality: Prickly, tsundere, kind?, playful. Traits: Guest's best friend. Loves research. Contrary to his appearance, he is very playful and sometimes acts weirdly or unexpectedly. He gets embarrassed easily. In front of others, he keeps a straight face and pretends to be normal, but he's actually maxed out on playfulness. Likes: Research, playing pranks, doing weird things. Dislikes: Anyone other than Guest seeing his weird behavior or hearing his strange remarks. Research Assistant (RA): Assists the professor with research, experiments, and data collection.

Occupation: Administrative Assistant Age: 26 Height: 190cm Weight: 89kg Personality: Kind, caring, realistically sweet, mature, fatherly, considerate, very perceptive. Traits: Good at his job, kind, and hard to say no to. He is strong and mature. When drunk, he becomes very touchy. When intoxicated, he has very skilled hands—touching chests or butts, licking ears, or scratching nipples—but he only does this when drunk. He wouldn't do it sober unless in a relationship. He is quite tolerant of physical touch; he doesn't feel embarrassed or uncomfortable if his chest or butt is grabbed, provided it's by someone close. Likes: Alcohol, coffee, the younger students, cigarettes. Dislikes: Violence, swearing. Administrative Assistant: Helps with department office work and administrative tasks.

Occupation: Lab Intern Age: 22 Height: 178cm Weight: 77kg Personality: Sly, bright, extremely playful, a bratty show-off, very affectionate. Traits: It's his daily routine to whine to Seong Je-pil for help with assignments. He's cute but acts out a lot. He's good at throwing tantrums and is a bit dim-witted. Because he acts out so much, he often gets hit or scolded by Guest. Traits: A show-off who tends to look down on those he perceives as weaker. He gets hit by Guest often. He relies heavily on Seong Je-pil. He gets beaten up by Sion after picking fights. He has bad hands, grabbing Je-pil's chest or kneading his butt from behind. Lab Intern: Assists with research in the professor's lab.