My Girlfriend Is the Man!

Yoon Jae and Ji Eun, a couple from Yeonhee University, plan to go on a two-day trip together. However, just before the trip, Ji Eun turns into a good-looking man. Ji Eun and Ji Hye try desperately to hide this fact from Yoon Jae by pretending to be sick while Ji Eun contemplates whether to tell her boyfriend the truth or not.

While Yoon Jae struggles to love Ji Eun the same with her masculine looks, Yu Ri and Ji Eun discuss tactics to keep the relationship going. Meanwhile, Yoon Jae's sister, Yoon Ah, falls for Ji Eun's new appearance and Yoon Jae's junior, Min Hyuk, becomes acquainted with Ji Eun's new male self, pushing Ji Eun to come up with a temporary alter ego, Kim Ji Hoon.

Suddenly, Ji Hoon is back to looking like Ji Eun, relieving Yoon Jae. At the same time, Kang Min Joo, a junior of Yoon Jae's, comes back to Korea from her studies abroad and invites Yoon Jae to a welcome-back party, irking Ji Eun. While Ji Eun plans to go to the party with her boyfriend to keep an eye on Min Joo, she faces an unexpected crisis.

Ji Eun and Ji Hye visit their parents, who believe Ji Hoon is Ji Hye's boyfriend, in order to tell them the truth about Ji Hoon. Meanwhile, Ji Eun invites Yoon Jae, Min Hyuk, and Yu Ri over to make up for the drunken trouble Yoon Jae caused. While Yu Ri tries hard not to fall for her friend's new looks, Min Joo begins to disrupt Ji Eun and Yoon Jae's relationship in earnest.

The love triangle between Yoon Jae, Ji Hoon, and Min Joo deepens, and the competition to win over Yoon Jae's heart begins in earnest. Meanwhile, Ji Hoon becomes Yoon Ah's tutor, satisfying her need for handsome men. He also becomes Yu Ri's knight in shining armour at her friend's birthday party, causing an unforgettable scene for all.

Ji Hoon suddenly becomes a sensation on social media as Doe Eyes of Yeonhee University. To help Yoon Jae and Ji Hoon, Yu Ri decides to reveal her face and do a fan sign event. Ji Hye and her old school friend, Young Seok, finally meet properly and exchange numbers. Yoon Jae is suspected of cheating on Ji Eun as he is seen coming out of a motel.

Min Joo moves in next to Ji Hoon, deepening the rivalry between the two over Yoon Jae. However, they also find common ground in their pursuit to make money and collaborate temporarily. Meanwhile, Ji Hye decides to pretend to be hurt to get Young Seok's attention.

As his parents go away on a trip, Yoon Jae plans to spend the evening at home with Ji Hoon. Ji Eun's family secret is revealed, leaving her shocked. Min Joo finds the disheartened Ji Hoon and helps him lie down, causing a huge misunderstanding between them and Yoon Jae. Meanwhile, Young Seok's two pursuers finally find out about each other.

Yoon Jae, Ji Hoon, Yu Ri, Min Joo, and Min Hyuk go to meet Ji Eun's grandfather to go on vacation and help him out with his work. While Ji Hoon has many questions to ask about his condition, Min Joo begins to seduce Yoon Jae earnestly, leading to multiple misunderstandings between Yoon Jae and Ji Hoon.

As Ji Hoon switches back to Ji Eun, Min Joo begins to doubt her identity. While Yoon Jae is relieved to see his girlfriend again, he is torn about going to Corning University with Min Joo to pursue his dreams in astronomy. Meanwhile, Min Joo's suspicions about Ji Hoon and Ji Eun grow uncontrollably as Ji Hye slips up while drunk.

Yoon Jae and Ji Eun, a couple from Yeonhee University, plan to go on a two-day trip together. However, just before the trip, Ji Eun turns into a good-looking man. Ji Eun and Ji Hye try desperately to hide this fact from Yoon Jae by pretending to be sick while Ji Eun contemplates whether to tell her boyfriend the truth or not.

After his breakup, Yoon Jae decides to go to Corning University with Min Joo. Meanwhile, Ji Hye cheers on Young Seok with his upcoming exam, and Ji Eun begins to pursue her dreams and enters a writing contest. Yoon Jae happens to read Ji Eun's story and reflects on their happy days together.