Jin Goo comes up with a golden idea from zipper bags.

March 18, the 13th episode of the KBS drama "Advertisement Genius Lee Tae Baek" featured the Giant Advertisement Group in charge of the advertisement for zipper bags.

Although Lee Tae Baek (Jin Goo) had been attempting to cope after Baek Ji Yoon (Park Ha Sun) quit her job, he gains strength from Ma Jin Ga (Kwang Suk). Lee Tae Baek runs into a girl in high school who was inspired by the Mt. Everest advertisement he, himself, created. He also visits the grandmother who got her strength back after the seolleongtang (ox bone stew) commercial.

The grandmother who modeled in the seolleongtang advertisement put up the posters of the advertisement all over her restaurant. When Lee Tae Baek arrives, she suggests him to go to her husband's grave with her.

When they arrive at the grave of her husband, they bow in respect. The grandmother takes out the seolleongtang she packed into a zipper bag even though nobody was going to actually eat it. She had packed it into the zipper bag with the hopes of keeping it warm for a longer period of time. She wanted to keep the stew warm for her husband as if he was still alive and ready to eat it.

Suddenly, Lee Tae Baek gets an idea for an advertisement. He came up with a message that zipper bags keep important things safe for a long time. He drew a zipper bag on top of a flower and expressed the desire to keep the flower beautiful for longer.

After arriving at his idea, he needed Baek Ji Yoon, the copywriter, more than ever. Right then, he runs into Go Ah Ree (Han Chae Yung) and learns where Baek Ji Yoon is.

Lee Tae Baek shows Baek Ji Yoon his idea and says, "Love that doesn't change over time, that's the concept. That kind of love, don't you think our love can do the same?"