[3rd Person POV]
Kihyun sighed as he sat on the floor in his room with all the folders and files Kyungah had given him spread all over the floor. He wasn't sure where Kyungah had managed to find them since he had tried to collect all the important things he could before he left the house. Maybe his parents had some secret hiding places he didn't know about. Maybe these folders and files contained things that even he didn't know. But now he thought it was time to look at them, sooner rather than later. 
After going through several documents which showed nothing important, he pulled out a piece of paper which was something of Kyungah's. It looked like a medical report but it was written in English.
"Why is this here..." Kihyun stuttered with confusion before he remembered of the time when Kyungah was in America and she needed a blood test as she was feeling unwell. When she had the blood test, she sent the medical report to their mother for her to look at as their mother had majored in English in the past, and this medical report also included Kyungah's blood type which was written at the top of the page.
Kihyun looked closer as he frowned, Kyungah's blood type was highlighted by a red circle with a question mark at the side. Their mother must have done this as there was also a note, in their mother's writing, on the side saying 'check blood type as soon as possible'. 

And that was when Kihyun saw it. He frowned as he held the piece of paper up in the air and even closer to his face. "How. How can it." He said perplexed as he dropped the piece of paper on the floor. The piece of paper which settled on the floor read the words 'blood type A'. 
Kihyun sat with his head in his hands, completely frozen. If Kyungah's blood type was A, and his own blood type was O.. what were their parents' blood types..? He knew siblings could have different blood types but something didn't feel right. Kihyun began scrambling through the rest of the papers in the folder, if this was a folder full of medical documents, surely their parents blood types would be in here too. 
Just as Kihyun reached the end of the folder, he finally found what he was looking for. It was a piece of paper which his mother had written down all the important medical information for the family.
Kihyun's mind became even more confused as he read the piece of paper closely. If their mother's blood type was B, and their father's blood type was O, it would make sense for Kihyun's blood type to also be O, but how could Kyungah's blood type be A..? It was impossible. 
"Are you ok? You're too quiet, is something wrong?" Kihyun heard Minhyuk ask him as his head appeared around the door frame. 
"There's something seriously wrong..." Kihyun stuttered as he sighed deeply. Minhyuk frowned as he approached Kihyun and sat down beside him.
After Kihyun explained everything to Minhyuk, they both sat and sighed. "There's only one thing you can do." Minhyuk said as Kihyun looked up with a curious expression, "You could do one of those sibling dna tests to find out if you're related, but that means you would need to tell Kyungah..."

~ 

Kihyun opened the door as he was met with Kyungah and Changkyun waiting outside. He was surprised as he saw Kyungah and she was waving happily to him. He let them both inside as he closed the door and followed them in. All he could think about was Kyungah, he sighed quietly as he watched her smiling and greeting Minhyuk, and chatting to him. She looked so happy despite everything that was happening, he couldn't tell her yet, not until he was completely sure. 
"Did you look through the documents?" Kyungah asked Kihyun as he immediately shook his head. Minhyuk glanced at Kihyun as he glanced back at him. Both of them knew it wasn't good lying to Kyungah, but it was for the best.
After Kihyun filled up two cups of water before passing them to Kyungah and Changkyun, he watched closely as Kyungah thanked him and took a sip out of the yellow cup. "Will you let me know when you've looked through the documents?" Kyungah asked Kihyun as he nodded his head to her with a smile. As soon as Kihyun knew what the documents meant, he knew he needed to tell Kyungah, he knew it would be something he wouldn't be able to hide from her.
"So where are you two heading?" Minhyuk asked Kyungah and Changkyun, changing the subject as Kihyun sighed quietly with relief. "Is it a date?!" Minhyuk gasped with a grin as Kyungah shook her head but Changkyun nodded his without Kyungah seeing. Everyone laughed as they continued chatting happily together.

As soon as Kyungah and Changkyun had left, Kihyun let out a loud sigh of relief. "I thought you were going to tell her?" Minhyuk asked Kihyun with a confused expression but Kihyun shook his head.
"I need to do something first" Kihyun told him as Minhyuk shook his head and disappeared into his room. Kihyun sighed as he carefully picked up all the mugs on the coffee table, pushing the yellow mug to one side to separate it from the rest.
"What's going on? I just passed Kyungah and Changkyun outside." Hyunwoo asked as he closed the front door behind him which made Kihyun jump slightly. "Did they tell you something?" Hyunwoo said nervously as he could feel himself beginning to sweat.
"No they just cam