During a high school music exam to assess the singing abilities of students, Songju shows off his rapping skills despite the blackboard in the background stating that pop and rap songs are not allowed. The teacher gives him an F on the test without saying anything. In the meantime, on one side of the classroom, Juyeon looks happy, watching Songju rap. He loves hip-hop as much as Songju does although these two come from completely different backgrounds. Songju is a troubled student living in a multi-house home in a less developed area while Juyeon is an exemplary student living in a fancy apartment in a rich village. Despite differences in grade, personality, and background, they decide to form a hip-hop duo called LIMECRIME.

High school seniors Inhye and Seohee build a shelter on a secluded plain, taking along the orphaned duckling, 'Heesun'. One day, when the school zoo they manage is threatened with closure, they recruit their classmates Jungae and Sumin from the Early Decision class and devise a plan together. They rescue the animals from the zoo and bring them to the plain. To fill the empty zoo, they buy animals from the market. They care for the shelter animals and spend joyful time together, calling their group the 'The Gorals'. In the second semester, they hear avian flu outbreak news, and the zoo animals will be culled. Feeling responsible for the animals they purchased from the market, they attempt to rescue them but fail; their shelter is also destroyed. 'The Gorals' are reunited for the last time, and they start a journey to find Heesun's home.