Changsub is joined by Key (from SHINee) as he reviews Seoul National University's Broadcasting Club during winter vacation.

It's the start of the first semester and Jeongwaja returns to change majors again! Lee Changsub goes to the Department of Business Administration, the largest number of departments in Korea. From marketing classes, which are the foundation of business administration, to how to be flattered at work?

To go to the same school as Yim Siwan, Jeongwaja commutes for 10 hours! Lee Changsub learns Mechanical Engineering with a special lecture on real Busan dialect from the local and fundamentals of machine that is easily(?) learned with Legos and robots.

Lee Changsub takes physics class, which is known to be a class that only real fans of science take! Starting with Interstellar's quantum mechanics and even an experiment that can win the Nobel Prize(?), Ant-Man, Doctor Strange...is it possible in real life?

From shampooing to drying and cutting, Lee Changsub goes to the Division of Beauty Art and experiences a full course at a hair salon by majoring in Hair Design!

Lee Changsub takes a class in the Department of Architecture that says staying up all night is basic! Taking a class at a construction site blowing cement powder and a design class where the professor buys chicken, Jeongwaja finally finds his talent?

From storytelling to nonverbal communication method, Lee Changsub learns everything by visiting Media Communication, a popular liberal arts department! With a surprise appearance of colleagues at work, Jeongwaja goes back to his main job?

Lee Changsub goes to the Department of Companion Animal Health where he took classes with Shiba (not swearing)! From making pet food that even people covet to pet training tips that surpass Kang Hyung-wook, how will Jeongwaja (aka Guri's daddy)'s adaptation period to the Department of Companion Animal Health be?

From the mystery of the birth of life to urgent real emergency room case practice, Lee Changsub learns in Ajou University's Department of Nursing! How does one respond to an emergency room patient? Jeongwaja shows us how!

Jeongwaja goes to Hansung University's Department of Fashion Design to become a fashion leader of the new generation! Lee Changsub tries to make clothes himself and even does the fitting! Let's check his fashion sense!

Lee Changsub goes to the Department of Hotel Culinary Arts and tastes heavenly food! A Jeongwaja who receives a special secret from Professor Lee Yeon-bok and Professor Jung Ho-young is reborn as a Cooking Master Boy, in one day?