Chaos
There was something called the chaos butterfly effect theory. A chaos butterfly was an example of how small insignificant actions could have huge consequences. This was the chaos butterfly theory: a harmless butterfly flying around flaps its wings, and that little flap sets into motion air currents that cause a gigantic roaring typhoon in the pacific or something. Small actions had grand consequences.
Something like this is about to happen.
A man, an unimportant man that really doesn't have anything to do with the story, gets up. He switches on the television, there is nothing on. If he had bothered to flip the channels just for thirty more seconds he would have found an interesting movie, watched it, and decided to marry a girl that looked like the heroine, married a girl that looked like the heroine, conceived a son who was charismatic and honest and hardworking, and the son would have eventually become the president of the United states of America and manage to pay all of Americas debt within three years and bringing forth the golden age. Unfortunately he didn't bother flipping the channels for just a measly thirty more seconds and instead turns off the television with a bored sigh.
He decided to go on a walk. He grabs his coat and forgets to bring his wallet, now this is vital to the chaos butterfly effect, seriously. He walks outside and walks at random. He sees a fork in the road and takes right. If he'd taken left he'd eventually walked through a dark alley where he would be assaulted by a mugger who would stab him because he'd forgotten his wallet. But he took the right. It leads to the park. The man sees an ice cream stand and walks over suddenly feeling a craving for some strawberry ice cream. He reaches into his pocket and retrieves the only thing in his pocket, a receipt for some milk and Trojan condoms he still hasn't had the opportunity to use. He growls and throws the receipt at the ground and stalks off.
A girl sees this and curiously picks up the receipt and turns to her mother and asks her what condoms are. Her mother flushed and told her to get rid of that garbage and buys her an ice cream to distract her from the question. The girl asks her brother later what a condom is who actually tells her the truth, she now needs to know what sex is so she Goggles it. She immediately gives her virginity to the first boy that shows her interest after her first period five years later when she'd thirteen because she is very intimate with the idea of sex and internet porn, a miracle she discovered at the mere age of eight thanks to a condom receipt.
This boy who has lost his virginity at the ripe age of thirteen boasts it to his friends, showing pictures she let him take as proof. One of his friends, who is still a virgin and will stay so for eleven more years, sulks for the rest of the week. His mother who is worried for him decides to make his favorite dinner which is coincidentally fish sticks, her husband hates fish sticks with a passion and they get into a heated argument that ends with the wife stabbing her husband. Shocked at what she has done she kills herself. That is what her son comes home to. This traumatic experience makes him run out of the house crying hysterically.
As he runs down the street like a maniac he bumps into a certain man that has everything to do with this story. The man is twenty one years old and is a part-time cashier that is living the life, and due to his grumpy attitude is depressingly single (even though he wouldn't admit to it being depressing even if you ripped his limbs off one by one). The man is holding a paper bag full of vegetables that he has just bought. As the hysterical boy bumps into him he drops the bag and the vegetables spill out everywhere and he swears.
He bends down to pick up his vegetables and a white haired man across the street sees him. The white haired man, who is a well-meaning Samaritan who commits a good deed every time he gets the chance, walks across the street over to the swearing man and helps him pick up his vegetables. He smiles at the other man and notes his androgynous beauty, his long blueish hair, what suspiciously looks like a sword hanging of his belt. The long haired man in turn takes note of the Samaritan's snow white hair and unusual pentagram scar and how he's wearing gloves despite the hot day.
"Hi, my names Allen, Allen Walker." Allen Walker says bringing out his hand to shake.
"Kanda," Kanda says simply as he shakes the hand.
He isn't one to shake hands when offered but the guy had just helped him out for no reason, not that meant he was obligated to be nice to the freak or anything but Kanda guessed he shouldn't be an asshole until given a reason.
And that was the beginning of a long and colorful relationship.
So because the man didn't flip through the channels for just thirty more seconds, because he took the right road, because he threw down the condom receipt in anger, because that little girl found out about sex early on in life and gave herself to the first boy who asked, because that boy bragged, because that boy's friend sulked, because that boy's mother tried to make his favorite food to cheer him up, because the enraged father got into a fight with his wife, because the wife lost control of herself and stabbed her husband, because she killed herself, because the son found them and ran out of the house screaming, because he bumped into Kanda, because he dropped his groceries, because Allen happened to see him and help him out, something amazing happened.
Allen and Kanda met, they talked, got to know each other, had their first fight and many more, drunkenly shared their life stories, traded phone numbers on an impulse, called each other, hung out, found out the other's interests, favorites, preferences, hobbies, tastes and ticks and pet peeves.
And they did some pretty awesome stuff together as well.
They got into a feud with the Noah family after a series of coincidences, stole a golf cart and were chased by a bull, accidentally ate happy brownies, celebrated New Years together, met some Chinese chick called Lenalee and her boyfriend Lavi who instantly declared Kanda as his best friend, they gave each other nicknames meant to annoy, got some scars together, got into fights, got into a car crash, delivered Lenalee's baby while in traffic inside a taxi, escaped Road's and Tyki's wrath, went scuba diving just because, watched Die Hard, learned that Kanda was allergic to peanuts the hard way, had dozens of zombie debates, and snuck into a post office through the vents.
Also they fell in love.
That was the chaos butterfly effect. And certainly, Allen and Kanda's love really did resemble a gigantic roaring typhoon in the pacific. It was unpredictable, dangerous, exciting, and a true unbeatable force of nature.
This fic was entirely based of the web comic Subnormality. Google it sometime, it's worth a quick Google, you'll love it, trust me.