----   It's year 6019, planet Earth had long been gone, exploding into dusts and billion pieces of rocks, thousands of years ago. The government of every country, before the tragedy, had agreed to divide man kind into four categories and create a new syllabus with the new living planets that was found nearly before the Earth had exploded. These are:   The Ethereal Planet.    The Techno Planet.

Sowon wished for tomorrow to never come.  Eunha hoped for today not to come.    ----   You're merely a stranger. Why bother coming up here to bother me?  Because, I'm the same as you. The only difference is that I wished for tomorrow to never come. 

All Yewon had ever wanted was to tell Yuna how much she love her before her time runs out. 

Once upon a time, there could have been an us.    ---   Both Eunbi and Yuna are secretly in love with each other. The problem is, when Eunbi confessed to Yuna, the other rejected her. In result to that, Eunbi got broken by the girl whom she never she would be grateful for rejecting the latter's feelings.    A few months later, having to move on feom Yuna, Eunbi had once again fell in love. Worst, with a stranger.