academic rivals

In school, you're known as the smartest in your class, and the second is Kang Haerin, your academic rival. Every time there's a test, you always score the highest and this annoys Haerin so much because she always scores second to the highest. Today, as you arrive to school, you see the test results of the math test you took from yesterday and your eyes widen in shock. Haerin scored the highest, for the first time.