"wake up, Yoongie !" Yoona awake from sound sleep as hearing a loud voice from Mr Kang Hodong, the Math teacher of her class.

" i want u to settle the question on the board , QUICK ! " said Mr Hodong.

" bo? Yoona's face started redness of shame.She hide all sense of shame and out to the front with blank expression.

On the board,  recorded question, x2-y=? Yoona answer, "sir,so easily.x2-y?y fall, then y ask for help but there's no one wanna help so the answer is x2 :)

Mr Hodong dumbfounded after hearing the answer.Everyone in the class rang with laughter.Mr Hodong ask Yoona to sit back at her place. 

Yoona school in Miraie High School that is the quite famous school and located at the Seoul.Yoona is the smartest student in looking for excuses. She also do not like to finished her homeworks unless forced to. Her class is inhabited by 25 students and were named as 'Lukewarm Clever'.All students sit in pairs except for Yoona.This is because anyone who sits next to her will be questioned by the teachers.

Yoona live with her haraboji and halmonim after her parents divorced.Everyday,after back from school,she will help haraboji at the stall that is Ramen Original Recipe.She will be the waitress or a cashier there while haraboji will manage all things at the kitchen with his few worker.That's the only source that can help them to pay medical for halmonim.