Kang soo and Jae-yi is a best buddies but Kang soo found out that he is adopted. He changed after that He don't talk to his brother and hates her brother too. Min-ji had a bullies but one day some app notify on her phone and says "Wanna get revenge? Download this!" Min-ji doesn't hesitate to download it and thought its a scam. Will it work? Can she get revenge using an app?