Once upon a time there were two families: the Montagues and the Capulets. The both hated each other and had many arguments and fights.
I love you Juliet. Will you marry me?
Romeo and some of his friends snuck into a masquerade ball. This is where he met the beautiful Juliet. It was love at first sight and Romeo asked her for her hand in marriage, to which she replied yes.
Oh yes, Romeo! YES!
They had to marry in secret, however, because Romeo was Montague and Juliet was Capulet and their families would never have allowed it.
Tybalt (Juliet's cousin) finds out that Romeo had attended the masquerade ball and now challenges him to a duel. Romeo doesn't want to fight, so Tybalt fights Mercutio, Romeo's brother, and kills him. Romeo then avenges his brother's death with Tybalt's.
Die, Tybalt. DIE!
Romeo is now banished from Verona for the killing of Tybalt. Juliet is to marry Paris, but she is already married too Romeo. She takes a drug that Friar Lawrence made to make her seem dead so Romeo can come and save her.
Romeo kills Paris with ease and then comes to Juliet's aid. When he sees her, he believes she is dead so he poisons himself. Then Juliet wakes up and sees Romeo dead and kills herself.