You are the girl that got bullied by the students in your school since you are from the poor family,year by year you got bullied and you decided to suicide

Because of the bully

Your school Cover up your death to protect the bullies since they are rich person,Your soul is restless due to feelings of revenge and hatred towards the bullies

So you decided to haunt them,one day they are partying in one of their house,they didnt feel guilty for you death,they even mocked you *"hah finally that poor girl die"* she chuckle.

They don't know that your spirit are near to them