On the day of SAT, which continued to take place even in the era of zombies, high school girls drive themselves to the place of examination.

After graduating with a degree in creative writing, 30-something Su-yeon abandoned the literary world and took to writing romance web novels. Her material comes from casual encounters she arranges through a dating app but her perception of love and sexuality is distorted. One day, she is visited by Jeong-ahn, a former university classmate who approaches her with a proposition—to expos Professor Shin Seung-hwan, who had sexually assaulted students during their university years. Su-yeon’s answer is unexpected, but soon after, she receives a message from Professor Shin, urging her to take his side. As a result, the stability of her daily life begins to unravel.

With 200 days left before college entrance exams, In-hye, who cares for the school's animal pen, spends her time lecturing a duck instead of studying. Seo-hee, punished for carrying a knife, joins her, and they discover an abandoned meadow where they lose the duck, Hee-seon. Meanwhile, teacher Kim Ah-tae forms a college interview prep group for four neglected students. On interview day, In-hye and Seo-hee ditch school to find Hee-seon, camping in the meadow and gradually learning to survive in the wild.