What makes a bond 'strong'? Kazuki had asked herself that question several times over the last two months. Was it intimacy? Comfort? Agreement? Whatever it was, it seemed like she wouldn't get her answer any time soon.

Kazuki had a person she truly cared about by her side, but he kept suffering. She wanted to reach his heart, but no matter what she tried, it seemed like nothing would work. She had done idiotic things, like dress in semi-transparent clothes, in order to take Yuuji's attention away from work...

"Haah." Kazuki sighed, recalling what had become of Yuuji.

Initially, he tackled the work without a shred of hesitation. However, after the first two days, he began to falter - almost as if he had just realized what he was doing. Yuuji knew he would eventually start breaking down; he had taken on the job of the man who killed the only person he'd ever loved, after all. After two weeks, Yuuji seemed to have become a hollow husk, living only to work.

No matter how hard Kazuki tried to cheer him up, he would simply keep working on the letters. She had started doing things as ridiculous as walking around near-naked in order to catch his attention, but it only got her an encouragement to cease doing so. She knew Yuuji's pain was great, but she was starting to feel unsettled by the change Yuuji was experiencing. While she was inside the Thanatos System, she took great care to look over his personal life with Kusakabe Asako - and she predicted that there was a 70% chance Yuuji would break down within the first three months of work. She had planned for it from day one, but it was painful to see him like that all the same.

Kazuki wanted to take his burden. She didn't care about how unhappy she may become; she wanted to do something for the only person in the world she truly cared about. She may be the girl who operated the SIGINT system Thanatos, but she still had 'emotions'. She was a human, after all.

Over the course of the last two months, she had gotten used to everyday life as a member of the Oslo Corporation. She was given a personal chamber, that is, a room, in which she often holed herself up in. She planned to read novels for amusement, but she always ended up staring into the distance thinking.

What can I do for him? How can I reach him? Kazuki was so frustrated she threw the book she was reading at the television, causing it to fall over and break in a million pieces. She was the Thanatos System - so why is it that she couldn't do something as easy as helping her own brother?!

The first time Yuuji broke down he was checking over the personnel list in his room. No one other than Kazuki was allowed to freely walk into the room, so he didn't restrain himself, knowing there would be no backlash. When Kazuki walked into the room, she found Yuuji spilling tears over the paper of the personnel. Yuuji always was a frail person, deep down, but he never allowed himself to show it to anyone.

His thoughts back then were on the lines of, I am doing the same job as the person who killed Asako. I'm disgusting... revolting... repulsive... He truly hated his weakness, his flaw of being overly sensitive - but he didn't know how to live any other way.

Kazuki felt hurt, frustrated, angry - she wanted to do something for him, but she didn't know what. The great Thanatos System, that which knows all, is unable to do anything? It was no exaggeration to call that the most reoccurring thought she had. Her anger had reached absurd levels - she even ended up hurting herself from punching things at random.

Her character had started to break because of the developments. As she looked down at her bloodied hands, she thought, so this is what it feels like to be powerless huh?

In the end, she arrived at an answer.

Love. So much love the world won't matter anymore.

She knew extremely well they were blood-related siblings; she also knew that Yuuji had never taken any girl seriously before. He had never felt anyone to be a 'partner' to him. Asako was only a parent in the end, and as much as Yuuji loved her, he couldn't bring it any further than that. Hence, Kazuki had to show him there was greater love.

That was when Kazuki got herself together. She stopped lashing out and decided to use her all to heal her broken brother. For the first time in months, she took of the arm she used to operate the Thanatos System. Under it, she found that her skin was unsurprisingly sensible - but she decided to follow her plan. She made her way towards Yuuji's room, entered it and embraced him tightly.

"Your hand..." Yuuji noticed the change.

"Oh, this? It's not fake - I used to wear the metal arm over it in order to operate the System from a certain range." Kazuki tightened her grip on Yuuji's back, pulling her face into his chest.

"... Why?"

"Just leave it. It's going to be alright."

Kazuki started embracing Yuuji like that at random. Initially, it caused Yuuji's breakdowns to increase in frequency. Kazuki feared it be her fault, so she almost ceased in doing so - but Yuuji never rejected her. At some point, his expression when he was embraced started softening. He started hugging her back, snuggling inside her warmth. Every time that happened, it felt as if they'd drifted into a different world, one where no sadness and pain existed, and Kazuki felt that it started happening.

My brother is still there. She knew he was; she just had to insist enough and he'd be back to himself in no time. She knew he regretted the fact the girls from Mihama Academy had built the 'paradise' on the island he owed but he couldn't go to visit. She knew he blamed himself for every little shortcoming that he had.

Maybe that is why she started falling for him. He longed for complete purity, even he was so frail. He was far too bright - almost like a supernova. If you looked too long, your eyes may burn to ashes, but it was far too beautiful to look away.

It was the 11th of October, 2013, when Kazuki caught wind of something that frightened her to say the least. She knew Yuuji wouldn't like hearing about it, but if she managed it on her own she was sure he would never forgive her. Torn between telling or not telling, she decided to choose the option her brother would want her to choose.

She got out of the Tartarus core and quickly dressed herself up. The room she was in was quite narrow, but beyond the glass that separated her from the rest of the System, a lot of space was taken up by the physical suborganic computer.

"... How dull." The clothes she'd prepared today were purposefully non-transparent; she didn't want her brother to complain anymore, but she found them truly too much of burden on her body, since her body was still weak. Moving around a weight all the time felt tiring, so she only did so for the sake of her brother. Once she finished dressing, she slammed the door of the Thanatos room open and shut it behind her.

The sound of the automatic lock closing could hardly be heard over the sound of her footsteps. Once she reached her destination, namely Yuuji's office, she took a deep breath and made her way through its door. She found Yuuji working on some documents she told him to save for tomorrow - he clearly hadn't listened, but that was better than waking him up right now. There was no time to waste.

Her words rang through the room.

"Yuuji, we have a problem." Her abrupt declaration instantly drew Yuuji's attention. Her complexion looked bad; she probably had rushed a great deal in order to reach the room. "A part of the Oslo Corporation that didn't agree with your philosophy has taken control over a number of locations and weapons and is planning to destroy the world."

They had managed to fool the Thanatos system for so long, and didn't have much information. They only knew one thing - the peace they had struggled to maintain was now being trampled. Yuuji exhaled, steeled his determination and stood up from the chair.

"It seems like we have business to get to."