Yonghwa glanced at his phone, tossing it aside after he saw the time. He was supposed to be in his math class right now. Instead, he was lying on the flat roof of the school.

The sunshine felt good.

Yonghwa was supposed to have it all. He had the looks, the girls, the parents who were never home, the body, the fame, the title. Yet something felt wrong. Yonghwa found himself incapable of loving someone.

It was as if someone had taken his heart and ripped a hole at the bottom and as much as he tried to fill it up with the fake affection from girls, nothing worked. Something, or someone, was missing.

He had a feeling he knew who it was.

He had been in a car accident a few years back, three to be exact. He knew that when he first woke up, he had forgotten who his stepmother and stepsister were. He recovered that memory the day after. However, there was something they were hiding from them.

Someone they were hiding from him.

His other stepsister, Seohyun.

Why, he couldn’t figure out. He just knew that they did. He had caught his father and stepmother talking behind the closed doors of their room about it and that was how he found out that he had another stepsister.

He also found out that his stepmother had forced Seohyun’s real father to take her back, as if she was a possession that needed to be ridded of. To his surprise, his stepmother claimed that he had been extremely close to Seohyun. He had pressed closer to the door, desperate to hear more, but then the doorbell rang and he had to scurry away in order to avoid getting caught.

Once in a long while he would hear more about his mysterious stepsister.

Why couldn’t he remember her?

There were times when he wanted to ask Taeyeon about Seohyun, but he kept it all back, fearful that Taeyeon would tell his stepmother about his questioning and the truth would never be revealed.

But then, even if it was Seohyun that he was missing, there was no way that a mere stepsister could fill the void in his heart. Perhaps he had been born with the inability to love.

No matter.

Yonghwa reached for a cigarette and yanked one out of his friend’s pack, lighting the end, and sticking it into his mouth. When his friend complained, Yonghwa threw him a look and rolled his eyes.

“Let’s go,” he rose to his feet. “Daewon High is getting their butts kicked today.”

Their underclassman gang had beaten some of the students at Yonghwa’s school. And of course, as the jjang of the school, he had to go take care if it. No one picks on Seorim High and gets away with it. His two closest friends, Kang Minhyuk and Lee Jonghyun followed him out to their bikes and they left a pile of dust in their wake as they brought destruction to their enemies.

By the time Yonghwa returned home, it was already midnight. No one was home, not even that annoying stepsister of his. She left a note on the table, but he honestly couldn’t care less and chose to ignore it.

His curiosity had risen recently. And it was rare for Taeyeon to be absent from their house.

Yonghwa took the opportunity to rummage through her stuff and easily discovered her diary. The oldest entry dated back to the date of his accident. Returning back to the safely of his room, he locked the door and began reading through it.

Dear Diary,

Today was really scary. Yonghwa got into a huge accident. I arrived at the hospital not worried that he would die; I was worried that he would leave Seohyun unnie behind. Arriving home, however, I’m now worried that it’s going to be the other way around- Seohyun unnie’s going to the be one leaving.

Mom is sending Seohyun away.

I heard her talking to my stepfather while she thought I was asleep. She’s getting rid of Unnie because Yonghwa’s fallen in love with her and apparently falling in love with one’s stepsibling is forbidden. Yonghwa has a forbidden love. Seohyun loves him back, I can tell. Seohyun has a forbidden love. They love each other, yet they can’t love each other. Why is love so complicated?

Honestly though, Diary, I think there’s more to it than just that. Mom’s always hated Unnie, since before she got married to Yonghwa’s dad.

I don’t know what to do.

And Yonghwa is still unconscious.

The next entry was a few days later, the day that Yonghwa had woken up.

Dear Diary,

Yonghwa woke up today. But he’s too late. Seohyun disappeared three days ago. I miss her like crazy- sometimes to the point that I want to kill myself. She was the only one in this family who could understand me. She had that ability. She was the only one I got along with. She was the only one that Yonghwa got along with.

The most horrible event happened today.

Yonghwa doesn’t remember Seohyun.

Mom forbids me to ever speak of her name. She says she’ll send me to my father if I bring Seohyun up again.

The doctor says that sometimes the victim of such an extreme accident will forget those who are special to him or her.

Yonghwa forgot about Seohyun. She was extremely special to him. I think she’s the reason why he is still sane.

Yonghwa flipped the page and scanned though the rest, shock slowly numbing his body. He used to be able to love someone? And that someone was his own mysterious stepsister?

Dear Diary,

I don’t know what’s wrong with Yonghwa. He’s pushing everyone away. If Seohyun unnie were here, she would be able to talk to him. He’s turning demonic.

Dear Diary,

My mom is making this family fall apart. Seohyun was the glue between us siblings. And now she’s gone.

Dear Diary,

Yonghwa has turned into such a player! I can’t understand why.

Dear Diary,

I think Yonghwa’s still in love with Seohyun unnie and that’s why he keeps changing girls so fast. He himself probably isn’t aware of it though.

Dear Diary,

Today was Seohyun unnie’s seventeenth birthday.

Yonghwa couldn’t handle it anymore and shut the book, even though there were several more entries left to read.

The reason behind his empty heart… was really because of Seohyun?