Author's Note: The title is a reference to a thought experiment made by Isaac Arthur (of Science and Futurism with Isaac Arthur) as a demonstration of indeterminism, which heavily influenced Fuyutsuki's argument in this fic. /FaEkdQiweVE?si=TW13D56P_rF8wUrm&t=353
Additional Author's Note: while in the manga (which this is based on) Mari is 16 and Yui 21, obviously that won't do, so I've aged Mari up slightly. This probably fucks with her character a bit, but I'll try to remediate it for the sake of yuri.
Mari awoke to the sound of her alarm clock. Like always, she got up at the relatively early hour of 8. She stretched, and reached over to get her contacts, which she soon put in. After a bit of deliberation, she got up and walked over, finally turning off the alarm. (She keeps it away so she has to get up to turn it off, it keeps her from snoozing over and over).
She opened the door to her room to be met by her failsafe, her orange tabby Princess, coming to beg for food. With a chuckle, she went to the kitchen and fed her, along with herself. Then, after collecting her clothes for the day and putting her contacts away, she stepped into the shower. She took care of her long hair then embarked in the longest task of her morning. Carefully, she took a razor and shaved, methodically, over almost all of her body, something she does every other day. Finally done with that, she got out to dry herself, once her contacts were back in.
Today she was bold enough to wear a skirt. The same skirt, in fact, she wore as the uniform for a school she used to go to, before she got kicked out. Slowly she pulled up her pantyhose, up over her boxers. Once hooked, she slid her bra around and carefully pushed her falsies in. She looked at herself in the mirror once her outfit was complete and smiled softly, deciding not to tie up her hair today, moving on to her makeup. Makeup is an art, and just like on a canvas it's about messing with light and shadow to give the illusion of a shape. Mari was quite experienced in doing this, making her jawline look softer and whatever else people associated with femininity. Now, at 10:00 am, she was ready to go to school.
Yui, on the other hand, had barely gotten up. She drowsily ate breakfast, didn't bother with makeup, and saved the shower for the evening like a sane woman. She barely remembered to put on her glasses as she stumbled out the door. How people thought of her as a star student, she couldn't tell. Sure, she knew a lot and got good grades, and participated in class discussion, always doing well to draw parallels and connections between the material and other things, but in other aspects she was lacking. She rarely did well in group projects, usually disagreeing with partners' methodology and getting hissy about it, to the point she sometimes had to step out of the room to calm herself (preferable to the alternative). Her writing was great— when she could get herself to write. Most of the time though, she was fretting over phrasing it right, what to include and what not to, and over her failure to push through.
She was distracted from her thoughts by her arrival in the classroom. She took her usual seat at the leftmost front desk, beside the window and just in front of Mari, who was already present. She was about to return to her thoughts, gazing out the window, when the professor came in, begging her attention. Something about Fuyutsuki let her know that today, like many other days, they weren't doing any work, and instead he would go on a spiel. She liked these days, usually he talked about something interesting, drawing her attention away from the window and fully on him and his words. Often she made comments relating to it, which he appreciated, even though she technically wasn't supposed to. Unbeknownst to her, they were also Mari's favorite days because she got to watch Yui rather than paying too much attention.
Today, Fuyutsuki talked about chaos, and chaos theory. He spoke of Edward Lorenz' definition of chaos, when "the present determines the future, but the approximate present doesn't determine the approximate future." He also spoke of how in 1961, right here at Kyoto University Yoshisuke Ueda noted what he called "randomly transitional phenomena" in analogue computers, but did not publish his work due to a disagreeing advisor. So, it was Lorenz the same year that developed chaos theory, in regards to divergent weather conditions. Yui helpfully commented that this is where the concept of a "butterfly effect" comes from.
"Indeed," said Fuyutsuki, "and this is only in a deterministic system. Something as complicated as human interaction is chaotic on an additional level. You cannot determine, with certainty, how someone will react. You may have heard of six degrees of separation, and it's likely true. If you interact with someone, within six or so interactions it's plausible you could influence anyone anywhere in the world. As for now, I have a six sided die. I am aware that next period is lunch, and that one of you may be up to suggestions. I have 6 meals, all available in the cafeteria, assigned to each number."
He rolled the die. "Four. That coincides with the cheeseburger. One of you may, if you wish, choose to have a cheeseburger for lunch. One of you may, in the process thereof, meet the love of your life. Or, you may not. In any case, this single action, magnified by the choices of each and every one of you, will bubble up to influence the future of humanity."
The bell rang, and the professor smiled. "With that, have a nice lunch."
Having nothing to pack up, Yui and Mari were among the first to get up and leave the room. Having the same destination, they ended up walking side-by-side. Yui's smile beamed onto Mari, who turned away to hide her blush. In return Yui tilted her head like a puppy-dog to get a view of her face, only to see Mari blushing harder. The cherry on top was her giggle, something she was sure would stay with her forever. How could someone like Yui do this to her so easily? Once waiting in the cafeteria line, Mari fell in behind her.
That Rokobungi guy, in front of them both, took his lunch and walked off. Yui perked up, and Mari with her. The two of them walked to the counter-line.
"The one with the cheeseburger, please," She said, ever chipper. With Yui by her side, Mari felt confident enough to chime in with a "Me too!"
The old lady passed one along, sighing. "More of Fuyutsuki's kids… Sorry, but we've only got one."
At that Mari scoots away, muttering quietly "Oh, uh, she can have it. I'll take Set A instead." Yui again tilts her head.
"Really? Thank you, Mari, you're so kind." She wasn't really, at least not in her mind. She just didn't want to be a bother. She didn't make this known, however, simply voicing an "Eh.." before walking off with her lunch, only to hear Yui speak up.
"Hey, where're you going?" She stopped and turned around halfway, thinking the answer to be obvious. Why would Yui have such a simple question? "Ah, a table?"
Yui giggled again. Mari wasn't sure what she said that was funny, but the sound was nice nonetheless. "I mean, do you wanna sit with me and Kyoko?"
She gave a noncommittal "Meh," but stepped back to follow Yui to her table nonetheless. The two girls together sat across from Kyoko, who was intrigued by the newcomer to the table. She smirked, and Yui half-regretted inviting Mari to the table.
"Finally picked up your little admirer?" She teased, making Mari sputter and Yui confused.
Yui quietly questioned, "Huh? What do you mean by that?" Mari leaned away from her, not wanting her or Kyoko to have to explain further. Unfortunately for her, Kyoko seemingly lived for gossip.
"Oh come on, she stares at you like you stare out the window!" Her accusation is louder than Mari's comfortable with; Even if it weren't so personal, she just didn't like the volume and cringed away from it.
Yui seemed to understand that and coaxed Kyoko to quiet down by keeping her voice low herself. However, all wasn't well for Mari as she pinned the statement on her. "You do?" Her tone indicated that she wasn't weirded out or anything.
Despite this, Mari still tried to deflect. "Well, um, it's not an issue when she looks out the window, so what's the big deal?"
Kyoko again smirked and looked at Yui, rather than her. "You goof. Yui looks out the window because it's pretty outside. As for you…" She lets the statement finish itself.
"KoKo, come on, give her some slack. How she feels is none of your business, and unless she decides so, it's none of mine." Her call, along with the personal nickname, shuts her down, meriting a mouthed "Thank you," from Mari.
"Fine." After a few minutes of quiet eating, conversation eventually sprung back up. By the end of lunch when they went their separate ways, Mari felt a little less like an outsider in this new friend group of theirs. She pushed her thoughts aside for two more classes, unfortunately neither of them shared with Yui, and only let them bubble back up once she was safe and sound back in her dorm. Whatever this thing she had going on with Yui, she had to get over it. She would, inevitably, find out, and it would almost certainly be over then and there. Rare enough was a woman who was into other women, rarer still one into her. One that would accept her for being transexual so far existed only in her dreams.
Dreams which tonight she returned to. As per usual dreams are weird. There was something about a fall, she was on the floor with her legs spread apart, and Yui got a peek, despite her wearing boxers and hose. Dream logic is like that. But, dream Yui didn't mind, she just leaned down and gave Mari a hug, saying she doesn't mind and that she thinks she's pretty too.
That was a nice dream. Before anything more could happen, she was awoken once again. Today she woke up at 8:30, needing less time to shower since she shaved yesterday. Altogether, she was ready to go at 10:00 again. Outside she could see a storm brewing, one of the first throws of the rainy summer to come. She leaves early to try and dodge the rain, bringing her umbrella as a plan b. Lucky for her, she got into class and had a few minutes before the rain began. Oh well, she thought, as her eyes drifted from the maelstrom outside to look towards Yui's empty seat-
"Yui!" She exclaimed, causing a kid in the back catching up on missed sleep to jostle up. She left her stuff at her desk and grabbed her umbrella, running out of the classroom. She knew the girl in question would be coming from the south campus buildings so she ran out into the rain in that direction. Keeping her umbrella angled to protect herself, she kept moving, quickly coming to meet with her classmate who was getting wetter by the second. Mari hadn't thought this through, her umbrella's small size meant she had to get pretty close to her, enough to get herself wet, to protect the two of them from the growing downpour. She did it anyway.
"Thanks," said Yui, not needing to elaborate as the two of them began walking towards the school at a slower pace.
"It's no big deal, I guessed you would probably be caught in the rain, and I have an umbrella, so…" The small bubble of protection didn't give Mari much space to shyly edge away, so she just kept walking as she trailed off.
"Yeah… My umbrella broke a week or so ago and since then I've tried to dodge the rain when it comes. It didn't go so well this time, ehehe…" With that last little chuckle she looked at Mari for a response.
"I guess not. Such a shame, it messed up your hair. Those little curtains you have are all straight now instead of hugging your cheeks." She too looked at the girl beside her.
Yui brought her hand to her hair to confirm. "You're quite observant. Is it true, if you don't mind me asking?"
"Hm? Is what true," Mari wondered.
"That you think I'm pretty, like Kyoko said." Maybe it was wishful thinking on her part, but it sounded like Yui was just as interested in the answer as she was.
Mari, again, clammed up. "Oh, well uhm.." That tone in her voice made Mari consider that the answer the other wanted to hear and the one she wanted to give were one in the same. "Yeah… I do, how could I not?"
Yui smiled wide, shining like a sunbeam cutting through the clouds. "I knew it, the feeling's mutual." Mari nearly tripped, but with her help she kept herself on her feet.
She finally asked "You-uhh.. It is?" Cheerily, she confirmed, "Mhm!"
As if that weren't enough for Mari to hear, as they sat down Yui added "If it looks like it's gonna rain tomorrow, come pick me up from building 3, dorm room 18."
That's right nextdoor to me, she thought, Why must fate tempt me so? All she said aloud was "Oh, okay. I'll keep that in mind."
It felt like class couldn't be over soon enough.