Onew was getting payback for his younger brother(tae yang) who was dead by believing Jessica that you moved to France to get married. So Onew went to find Jessica to punish her for what she did to taeyang,but he actually caught you by accident.He was calling you "Jessica" because he saw the picture of you and taeyang together.Onew trapped you on an island that he own.You were very mad at onew because he keep on calling you Jessica and he keep on giving you hard chores.One day Onew found out that your real name was not Jessica so he went to apologize for you but you didn't care all you cares about is that you want to go home,but Onew don't want you to go because he was in love with you.Onew feel very sorry for what he had done to you,so he actually let you go home but before he let you go home he took you to his special place that he like,he took you to taeyang's grave,and he also bought you a pearl set of necklace,earrings,and bracelets that his workers make.He told you not to take it off because it's was the only gift he can give you for giveness and you are very special to onew's life. 

This is all the clue i can give you so go read and find out what happens