Jisoo is always beside Jeonghan.

First when they're toddlers, and know of nothing but the sugary sweetness of popsicles and the soft, gentle hands of their mothers. Jisoo tags along behind Jeonghan, being the responsible, shy one. He is the night to Jeonghan's day, their parents say playfully, and of course it's cemented from there. Jeonghan is the day and Jisoo is the night.

Next, they're grade-school kids, and Jisoo is quietly clutching onto Jeonghan's backpack, afraid to let go. It's terrifying to six-year-old Jisoo when Jeonghan tries to befriend a couple of kids. 

Who's the weird kid behind you? they ask.

Nobody, says Jeonghan.

Jeonghan is the day; warm and kind and friendly and loud.

Jisoo is the night; cold and shy and unlikeable and quiet.

Even though Jeonghan ignores him, Jisoo still watches from a distance, afraid to let go. He doesn't worry, because everyday when they get home, Jeonghan will lavish all of his attention on Jisoo and everything will be right in the world. And it is. For a long while.

That is, until high school. 

There is a boy named Hansol and he is like the evening; quiet, but there's a certain charm in him that Jisoo can't ignore. 

The moment that Hansol asks him out is the moment that Jisoo realizes: people like nighttime, too.

Of course, evening is always between day and night.

Jisoo begins to become distant from Jeonghan, always spending time with Hansol. He can't help it; the boy pays more attention to him that anyone ever has, and the low, gentle way he speaks is music to Jisoo's ears. 

Jeonghan often finds them curled up in the grass, whispering to each other in English, absorbed in their own little world.

Of course, when Hansol breaks up with Jisoo, Jeonghan is the first to wipe the tears away.

When they hug for the first time in four years, it's like two puzzle pieces clicking into place; they melt into each other and Jisoo knows it's so wrong to be so in love just after breaking up, but this just feels so right. 

They become day and night once again, hands naturally gravitating towards each other; always connected in some way. And Jisoo is beside Jeonghan once again.

It's not until university that Jisoo realizes the true meaning of day and night.

When he curls up in his dorm in Los Angeles and tries to video chat Jeonghan, he remembers that Jeonghan is probably asleep by now. And that's the real curse of day and night; they can never see each other.

They try to set up times, but one of them usually falls asleep before the call ends and the other quietly hangs up. It's a neverending cycle, because day and night never stop, and Jisoo realizes that he's ruining his marks and his social life, just to be with Jeonghan.

They spend a day planning to meet in Korea on Christmas Day. 

Jeonghan spends a day planning how to break up with his boyfriend. 

Of course, he never gets to, because Jisoo dies in an apartment fire a week before Christmas.

And that's when Jeonghan comes to the conclusion that day can't exist without night. 

There is no light without darkness. There is no noise without silence.

There is no Jeonghan without Jisoo.

But slowly, Jeonghan begins to learn that Jisoo is still beside him.

Jisoo's eyes are the shimmering stars in the sky. His breath is the soft, almost-cold-but-not-quite night breeze. His voice is the soft rustle of the moonlit trees.

Jeonghan is the day, and Jisoo is still very much the night.