At the age of 16, everyone will be given a nacklace that is purely made just for them. There's two types of necklace; 

The Key and The Lock

If you receive 'The Key' , it means you're the submissive one in the relationship whereas 'The Lock' means you're the dominant one. Like an alpha and omega thing except there's no beta and they aren't wolves. 

"Teacher!" A 13 year old Jungkook called out.

"Yes Jungkook?" 

"How does it work? Do the person with the keys just walk up to anyone with a lock and insert it?" 

Mr.Han chuckled and shook his head, "Well,this where it gets complicated" 

When a person is near their soulmate, the necklace will start to burn a bit. The person with the key will have this kind of an autopilot mode where the person will move automatically to any directions where their soulmate is. 

And this is the funny part that the universe has made as it is: 

As soon as the key meets the lock, the lock will immediately lock itself meaning the person is taken whereas the key remains the same but the gold colour will fade into a silver colour and let's just say the person will have their soulmate's name tattoed on their left wrist. 

"H-how..?" Jungkook was memerized. He did remembered his parents explaining that he'll have a soulmate soon but not this specifically. 

Mr.Han notices the amazement of the whole class and he smiles knowingly. 

"I know this is a lot to take in but in a few years, you guys will experience it yourself, just don't freak out yeah?" 

3 years had passed and tomorrow is Jungkook's birthday and he can't seem to sit down ever since. 

"Dude I know it's your birthday tomorrow so stop moving" Mingyu can only sigh as Jungkook kept moving around. 

"You have your necklace already! Why can't i have mine now?"  Jungkook asked in despair making Mingyu rolls his eyes. 

"Tomorrow Jeon Jungkook" 

"Tomorrow Jeon Jungkook" 

"Yah! Don't mock me!" Mingyu pouts and cross his arms.

"Or what? You're gonna call your soulmate and beat me up?" Jungkook asked with a knowing smirk. 

"You do know he's my brother right? Jeon Wonwoo" Jungkook laughs as Mingyu's face when beat read. "Shut up Jungkook and luckily he's out to practice" 

Jungkook smiles bashfully at his friend but deep down he's glad that Mingyu found his soulmate within months but at the same time, Jungkook can't help but feel jealous towards his friend. 

"Tomorrow is your birthday, so i'm betting you're getting the key" Mingyu says confidently and that manages to bring Jungkook back into reality.

"I'm a Jeon, my dad receives a Lock and Wonwoo receives a lock too" 

Mingyu gives me the look and shakes his head. "You look like you needed protection.. Even Wonwoo agrees with me!" 

"Because he's my older brother, of course he wants me to be protected" 

"You'll never know Jungkook"

"Open your eyes" 

Jungkook opened his eyes and instantly his hand goes to touch the necklace hanging on his neck. 

"My baby is all grown up now!" Eomma cooes and pinches Jungkook's cheeks. "Hopefully your soulmate takes care of you kiddo" Wonwoo ruffles Jungkook's hair. 

"What-" Jungkook stopped and notice that he has the key instead of the lock. 

"I knew it" Mingyu whispers but Jungkook ignores him, quite shock that he receives the key.

"Appa.." Jungkook trails off. Jungkook should've known, he let his family down.

Mr.Jeon was smiling proudly at his son without Jungkook's notice. Jungkook was busy blaming himself when Mr.Jeon hugged him. 

"Now i have reasons why i should be more protective of my child" Mr.Jeon halfs joke and is half serious. 

Mrs.Jeon and Wonwoo knows better that Mr.Jeon is serious but keeps quiet. 

"Appa~" Jungkook whines childishly and Mingyu sighs, no wonder he gets t