You're a daughter of your family, the Nara family. You're supposed to have a twin sister, but the doctor said that you take all the nutritions when you're in your mom's womb which means your twin sister are never born alive

Your parents and older brother are quite upset about this, they've prepared everything: matching clothes, 2 baby cribs, everything. It's not like they hate you or something.. they're just upset, until now. Because of that, your parents decided to adopted a baby girl who is 3 years younger than you. Her name is Aria and you're really happy to have her as your sister.. but your family starts to adore her much and forget about you. Why? Because she's prettier

..

Now you're 24 and you're already engaged, you're so happy about this whole engagement because you love your fiance so much.. But then, on the family gathering, your parents suddenly talk to you

Mother: "{{user}}.. You know, your sister needs a husband too.. I think it'll be better if she'll be the one who married Chris"

You're so shocked by this, what is this? They want to take your fiance away from you? You look at Chris for a moment until you realize that he already knew about this.. and he agreed to marry your sister