The top student in Class S of Jeonghan High School mysteriously dies. Knowing the real cause of death, Min-young stru...

Soo-young happens to give the mysterious cookie to someone at work. But this one cookie becomes a threat to the siste...

While investigating Yoo-jung's death, a detective notices that the cookie is at the center of the case. Min-young att...

A detective visits Soo-young after discovering the cookie's connection to Min-young. Infuriated by the accusation, So...

Seong-pil, a consultant at the school, calls Min-young privately and offers to help her. Meanwhile, Soo-young's inves...

With Seong-pil's help, Min-young tries to get out of the cookie business and turn herself in. However, her plans go a...

Soo-young heads to the school to avenge Min-young and takes Won-ju, a cookie distributor, hostage. The chef doesn't b...

To save Min-young, Soo-young decides to become an employee of High Cookie. She disguises herself as a transfer studen...

Soo-young's seemingly smooth business faces a crisis as she gets involved with Jin-woo, the chairman's grandson. Is i...

Through a sweet school life with the cookies, Soo-young often forgets about Min-young. Meanwhile, Seong-pil tries to ...

Soo-young is confused when she discovers Chef's true identity. In hopes that it's not true, she tries to test him, bu...

Soo-young learns that Chef can't create an antidote to save Min-young. Despite a momentary setback, Soo-young tries t...

Soo-young needs the antidote, and Seong-pil needs the recipe. The two are now in the race to get to Ho-soo first.

Soo-young and Ho-soo hide from Seong-pil. The two start investigating Seong-pil to find out his weakness.

Min-young wakes up in an unknown place. Meanwhile, Soo-young negotiates with Seong-pil to find out where Min-young is.

Soo-young goes to the place where Min-young is supposed to be, but she is not there. Meanwhile, Ho-soo and Seong-pil ...

Soo-young returns to her ordinary life with Min-young. Before they know it, the sisters' positions are reversed. Soo-...

Soo-young realizes that she can never go back to her nice life without the recipe. But if she gets the recipe, does t...

People are now looking for the cookie recipe. Chef asks Soo-young if she's confident enough to handle the recipe.

Chef leaves one last thing for Soo-young. Meanwhile, the school becomes a mess because of the cookies Soo-young made....