"Promise me that we will never fall in love. People will just take advantage of our feelings and leave us behind in the end. Don't worry, you won't be alon, we have each other, right?"

That's what you told me, but you just broke it...

- Oh Sehun and Bang Ha Jin were childhood friends. They are always with each other since day 1 of their lives. But things happened and the friends got seperated. Years passed, both 19, they both meet each other. But Ha Jin felt weird. Her Se Hun changed.