Season 1
Kim Min Gyu is the largest shareholder of a financial company. He suffers from a "human allergy", preventing him from normal interactions with other people. He becomes interested in a robotic project named Aji 3 created by the Santa Maria robotic team. The team is headed by Hong Baek Gyeon, inventor of Aji 3 and world-renowned robotics professor. He modeled Aji 3 after his ex-girlfriend, Jo Ji A, a struggling inventor that also works as a personal shopper to make ends meet. Just when Min Gyu wants to test the robot, an accident causes the malfunction of the robot's battery. Baek Gyeon begs Ji A to take the place of Aji 3 and pretend to be the robot so they can get funding from Min Gyu. But Aji 3 becomes the closest thing that the lonely Min Gyu has to real contact with another person.
01. I’m Fine Being Alone
Kim Min Gyu gets an allergic reaction when in contact with humans, but he says he isn't lonely.
02. Aji 3
Min Gyu orders Aji 3 for trial. But that night, the research team accidentally spills beer on it.
03. I Can Do Many Things for You
Ji A goes to Min Gyu's house. She makes her first mistake, but she must keep pretending she's a robot.
04. Welcome to My Home
Min Gyu decides to keep Ji A. Meanwhile, Ji A discovers Min Gyu is the head of KM Financial.
05. I am Glad You are a Robot
Min Gyu believes Ji A is a robot and agrees to train her for a month, making Ji A face many obstacles.
06. You Brought Back the Sunlight
Ji A discovers Min Gyu is her brother's boss. Meanwhile, Yoo Cheol hears about Santa Maria and Aji 3.
07. Painful Memories
The cause of Min Gyu's allergy is told. Also, Ji A saves Min Gyu's life when he gets an allergic reaction.
08. Beautiful Memories
Baek Gyeon wonders if it's okay for Ji A to stay with Min Gyu and realizes he still likes her.
09. I’m Cured
Min Gyu becomes hopeful of curing his allergy. But Baek Gyeon is mad that Min Gyu and Ji A are getting closer.
10. I’ll Protect You My Own Way
Baek Gyeon punches Min Gyu, brings Ji A home, and tells her she doesn't need to see Min Gyu anymore.
11. I Want to Kiss
When it is time for Ji A to leave, Min Gyu shows Baek Gyeon his allergic reaction to keep Ji A by his side.
12. This Is When You Must Kiss
Min Gyu learns how to kiss and tries to kiss Ri El on a date. Baek Gyeon follows them in secret.
13. A First Kiss Tastes of Apples
Ji A kisses Min Gyu first, which makes him feel confused and makes him keep a distance from her.
14. You are Concerned for Jo Ji A
When Baek Gyeon sees Min Gyu ordering Aji 3 to do household chores, he volunteers to do them himself.
15. I am Not a Robot
Baek Gyeon says Aji 3 will be ready in three days. Min Gyu goes on a date with Ri El and meets her dad.
16. One Person is Enough
Baek Gyeon realizes why Ji A broke up with him. Meanwhile, Yoo Cheol shows up at the start-up competition.
17. You Can Send Aji 3 Away Now
Baek Gyeon is shocked when Min Gyu says he likes Aji 3. Meanwhile, Dr. Oh tells Ji A about his allergy.
18. Seeing You is Too Hard for Me
Min Gyu tells Baek Gyeon how he always waits for Aji 3 to come, but he says Min Gyu is too lonely.
19. I’ll Recognize You
Ji A is sad about lying to Min Gyu. But Min Gyu has to reset her memory and misses her when she's gone.
20. What Do I Need to Do?
Min Gyu calls Ji A for a delivery service, but she rejects it. Meanwhile, Ji A sees Min Gyu with Ri El.
21. Encounter on the Train
Min Gyu sees Ji A on the train and follows her. Min Gyu almost finds out the truth about Ji A and Aji 3.
22. Geoje Island
Min Gyu tries to stop Ji A from going away, but Ji A tells him that she isn't Aji 3 but only a model for it.
23. The Truth
Locked up in a storage room, Min Gyu tells Ji A about his story. She feels sad but decides to leave him.
24. You Promised
Min Gyu ends up returning to the beach to see Ji A again. Meanwhile, he realizes Aji 3 kept a backup folder.
25. Have You Been Lying All Along?
Min Gyu discovers all about what Ji A has done to him. From the shock, Min Gyu gets an allergic reaction.
26. Ji A Knows Him Best
Ji A keeps coming to see Min Gyu. Meanwhile, Min Gyu finds out Ji A created the Heart Balls.
27. I Really Need You
Ji A and Min Gyu confess how they feel about each other. Meanwhile, Ri El hears that Yoo Cheol will marry her.
28. Just a Product Owned by a Man
When Martin becomes impatient, Do Won promises that Aji 3 will be ready soon. Min Gyu tries to protect Aji 3.
29. Aji 3 Disappeared?
Min Gyu tries to stop Do Won and bring Aji 3 back, but Aji 3 is nowhere to be found, making Martin furious.
30. Goodbye, Aji 3
Baek Gyeon decides to change Aji 3's face. He deletes every video except for the emotion patterns.
31. A New Beginning
Yoo Cheol learns about the cause of Min Gyu's allergy and decides what to do about the board meeting.
32. Final Episode
Ji A pursues her own dreams, while Min Gyu and Yoo Cheol become good partners in leading KM Financial.