1. You and I, the Intersection of Two Universes

As competition in her class ramps up, Nam Hae-e anxiously awaits her math score. Choi Chi-yeol is embroiled in a scandal involving one of his students.

2. Probability of Encountering Your Enemy at Your Worst

Nam Haeng-seon attempts to register Hae-e into The Pride Academy. Desperate for Haeng-seon's food, Chi-yeol visits her store in a disguise.

3. Number of Outcomes Where Dislike Becomes Like

Haeng-seon begins fawning over Chi-yeol after discovering his true identity. A change in the Pride Academy's schedule creates a stir among the parents.

4. Revolt of the Arithmetic Sequence

Haeng-seon gets a taste of the vicious politics among the academy's parents. She later goes to great lengths to make things right for Hae-e.

5. The Secret Probability Distribution of X and Y

Haeng-seon and Chi-yeol work out an arrangement for Hae-e's tutoring. A mysterious tragedy leaves the academy and its parents rattled.

6. There Are No Correct Answers in Life, Only Best Answers

A painful past comes back to haunt Chi-yeol. Bang Su-a becomes suspicious of Hae-e after finding her secret worksheets on her desk.

7. The Very Average Laws of Attraction

Hae-e ranks first in her class, causing drama among other parents. Chi-yeol and Haeng-seon grow closer as he spends more time with her family.

8. Chance Becomes Fate through Inductive Reasoning

Haeng-seon realizes her own feelings after seeing Chi-yeol at the academy. Su-a connects the dots and begins to make sense of Hae-e's recent successes.

9. The Butterfly Effect of Our Relationship

Chi-yeol and Haeng-seon deal with the fallout after their secret is discovered — forcing the two to confront what it means for them moving forward.

10. Emotion, the Variable That Alters Relationships

A public revelation leaves Haeng-seon and Chi-yeol's relationship in limbo. Meanwhile, Chi-yeol faces the repercussions of recent events.

11. The Functional Relationship of Our Love

Tired of her loved ones facing scrutiny, Hae-e makes a bold confession to the world. Haeng-seon and Chi-yeol navigate their road ahead post-scandal.

12. Point of Intersection between Comedy and Tragedy

A shocking arrest leaves the academy's parents — and Hae-e — concerned. Haeng-seon and Chi-yeol maneuver the days after their first fight.

13. How We Approach an Unsolvable Conjecture

Hae-e attempts to get a hold of Lee Sun-jae after being put in a difficult position at school. Haeng-seon catches Ji Dong-hui in a hostile moment.

14. Find the Unique Solution

News about Hae-e leaves those around her feeling rattled. Haeng-seon begins to suspect something's off. Chi-yeol confronts Dong-hui about his behavior.

16. You and I, the Union of Two Universes

Grappling with her mother's return, Hae-e announces a shocking decision. Haeng-seon and Chi-yeol make a pivotal choice about their future.