She flapped her soft, feathery wings as she crossed the line between her world and the other one. Between heaven and earth. It was her first visit on earth. Her first visit on the world full of corruption. She was a young angel. Unknowing, too. She was an excited angel. Curious, too. But above all, she was a pure angel.

She slowly flew down, through the full and fluffy clouds, of which she had been wondering how they'd feel like for so long already. And now that she finally had the chance to feel them, she felt let down. They weren't soft. They weren't fluffy. It was only wet. Wet as water is. Boring. The angel huffed before she quickened her pace. It hadn't been long since she crossed the line, so there was no need to be disappointed. Not yet. There was still the actual world, the sea, the cities, and above all, the humans.

Humans. She had heard so much about them already. Creatures that were able to both love and hate so strongly, so passionately at the same time. Creatures that could be so full of selfishness and selflessness. Creatures that could have a heart as big as the world or one as little as a dust grain.

Wondrous creatures.

And the angel was eager to find out more about them. She was eager to learn first-hand what those creatures were like. So many angels had been telling stories of the corruption in the world, of how even they, the pure angels, were affected by it. And yet, every angel who went down to earth wished to change the corruption with their radiance. This little one as well.

The angel took a deep breath as she finally left the clouds, the view in front of her becoming clearer. There it was: a city. Given, it was still far away, but at least it was recognizable. She could feel excitement rush through her and she flapped her wings more strongly, wanting to get closer to the city. She was soon going to see it, so of course she'd be excited, right?

Was it sincere excitement, though?

The wind up here was cold, but she didn't feel it. Because angels don't feel, can't feel. Because angels have an empty heart. A heart without strong emotions. Without real emotions. Ironically, that is what makes them so pure. Their emptiness. Because emptiness gives space for the morals they're taught. For the emotions they learn to feel. Happiness is one of them. Happiness is the only one. Other character traits – such as curiosity or helpfulness or the like – are part of an angel's nature. Because their minds are filled. But their hearts are empty.

Angels don't cry. Because the mind doesn't cry. Only the heart does.

They laugh, though. But not sincerely. They laugh manufactured laughs. Because the mind tells them, they're happy and therefore need to smile, need to laugh.

Angels don't know greed. Because the mind tells them it's wrong. Because they have no heart that lusts. Because they're pure.

Angels don't know hatred. Because only an envious heart, a greedy heart, a selfish heart can hate. Because theirs is empty.

This little angel could feel a wide smile spread across her face. She'd soon see the city. How will it look like? How will it smell like? But above all, how will it feel like?

Coming down to earth only has another purpose apart from wanting to lessen the corruption in the world: to teach angels how to feel. How to actually feel. To fill their hearts with real emotions. Not manufactured ones. In exchange, they'd give humans a bit of their purity. 

The manufactured excitement died, though, as the angel was met with the close sight of the city. It was grey. Just a big clump colored in grey. And this was supposed to teach her actual emotions? To teach her what those wondrous creatures were like? She narrowed her eyes a little as she landed on one of the skyscrapers.

The angel sat down to let her wings rest; the journey from heaven to earth was tiring. She looked around the city, her hazel eyes trailing the different shades of grey she was seeing. The buildings were of a dark shade, the trees of a lighter shade, and the humans? They were white. But not a healthy white. A sickish, pale color was gracing their faces.

Their faces were either expressionless or negative. Some were mumbling incoherent words about the bad weather. Others were focused on their cellphone screens with bland faces. Some were angrily pulling their crying children with them. Others were fighting with each other, crying and yelling.

The angel blinked. Once. Twice. Weren't humans supposed to teach her happiness? Weren't they considered so wondrous for being able to feel sincere happiness in a corrupted world? Why then was she only seeing anger, hate and sadness? Where was the happiness? The only emotion she wanted to take in was happiness. How come she couldn't spot it anywhere?

Maybe she needed to get nearer. Maybe she needed to stand beside them to see the positive emotions. Maybe the distance was blurring those with the grey color.

Little did she know, the distance was not the problem.

Just as the angel flapped her wings again to fly down, she spotted something from the corner of her eye. A figure. A human standing on the building. Her eyes widened at the sight and she turned around to fully see the figure. She wasn't afraid to be seen because that couldn't happen. Because angels can't be seen with a mere human eye. Because a human's corrupted gaze can't capture the angel's pure radiance.

It was the sight that shocked her.

What she knew about humans was facts. And one fact was that falling could kill humans. And the building she and the human were standing on was high. Too high.

The human, a boy, stood at the edge of the building, his expression empty. His face was of an even paler color than the other humans' faces she had seen before. But, he wasn't grey. It was a different color, an undefinable color.

The angel watched him with wide eyes. What was he doing up here? Was he aware of the danger? Danger was something angels would forever want to avoid. Danger meant only bad. That was what they were taught. Their morals.

As the boy with the tousled, black hair took a step forward, his foot only three inches from the end of the edge, the angel automatically shot forward.

She didn't know what he was doing, but couldn't hold back her body's movement as she rushed there, reached out and grabbed the boy's arm with both of her hands. With all the strength her petite body possessed, she tried to pull him away from the edge, despite knowing it was most-likely a futile attempt.

Her strength was little in this world. Because, not only was she invisible for the human eye, her touch was also barely perceivable for the human body. Because corruption and purity repel each other in direct contact.

And yet, it caused the boy to take a step back. Not because he had felt grip around his arm, but because he had felt something. Reluctance. The angel's pulling could be barely perceived by his body. But his heart. His heart had been affected by the pulling.

The angel sighed in relief upon seeing the step backward. But before she could observe the boy further and try to analyze the situation with what she had learned about humans, the sudden noise of a door banging against a wall snapped her out of her thoughts.

“There he is!” An unfamiliar voice yelled.

Instinctively, she stepped away from the boy and turned around. A group of people had arrived on the rooftop of this building. She frowned. What was this all about?

“Do Kyungsoo,” one of them said. It was the one who had yelled before, but now his voice was a lot calmer. “Before anything happens, Dr. Kim would like to talk with you first.”

“So would you please step away from their so we can talk?” The man continued and the angel noticed how he motioned the people behind him to come forth. She turned her head again, seeing that the boy – Do Kyungsoo if she had heard correctly – was still facing the city, back-facing the people who had arrived. He stayed silent and the angel assessed the tension that was filling the air. She flapped her wings and flew up a bit, watching the whole scene from a safe distance. Even though she couldn't be seen or touched, if she were to perceive too many different emotions at once by being close to so many humans, there was the high risk of breaking down because angels weren't used to so many emotions. There were many rules to learn before visiting earth because the visits bore dangers. It was the only danger angels were willing to take on.

Once in the air, she could see the boy's face again. And it wasn't blank anymore. There was uncertainty, wavering and tugging. There was fear, trembling and pulling.

But there was also something else. Something the angel couldn't pinpoint. Was it sadness? No, it was stronger than that. Was it anger? No, it was weaker than that. It was something she hadn't seen before.

However, before she could think about it further, his expression changed. It changed to surprise and shock, and the angel noticed that both of his arms were being grabbed, as well as his shoulders. Behind him were two men who had grabbed him and were now dragging him back.

His undefinable expression from earlier turned into something the angel could immediately recognize.

Anger. Burning and hot anger.

She could see him struggle heavily. She could see his attempts to get rid of those grips. She could see the punches he threw whenever one hand got free. She could see the glares he shot at those who were dragging him to the door.

But all the time, she hadn't heard him say anything.  

The angel just sat on the ground of the rooftop, even after the people had long dragged the boy away. When they had left, one of them had shaken his head, mumbling, “Youths and suicide these days …”

Suicide. She had heard it before. A word describing the act of intentionally killing oneself. That was the phrase she remembered having learned, having read about humans. That was one of the things she and the other angels had never understood about humans. Why would these wondrous creatures put an end to their lives? Such things remained at the back of an angel's mind. The dark side of humans, they weren't eager to learn about it. Which was why the angel had only thought about it upon hearing the word.

Her mind began to spin a little as the thought crossed it. So dark. So painful. It was so contrasting to the happiness she was seeking to learn about. She didn't want to be faced with negative emotions. She didn't want to think about this suicide any longer. However, she couldn't push away the image of the boy's face. Of his emotions. Of that undefinable one.

Not wanting to concentrate on such negativeness anymore, the angel stood up and flapped her wings to fly away. She didn't want to stay on this building any longer. She needed to observe the humans from close up. She still needed to find a happy human.

When she arrived at the ground, the streets, and was therefore amid a gust of emotions, she stumbled back to avoid the people. Although they weren't able to touch or see her, she would feel them walking through her. She would feel all emotions they were feeling, first-hand, as th