Senku x Reader [aphrodisiac]

1

(Y/N)'s traits: knows a bunch of math and science because of the time spent with senku, not naturally gifted in math, senku's lab partner/assistant due to their knowledge of his work behavior, dog-like, sleep-lover, passionate about psychology and neurology.

Disclaimer: The science of aphrodisiacs are altered for this story's plot line.

"Open up, idiot! It's already 7!"

Senku banged on the door of his neighbor's apartment. A (low/medium/high) pitch voice responded, mouth seemingly stuffed with food, leaving their message unintelligible.

The door swung open, revealing a (height) foot-tall (girl/boy/student) with cheeks full of (favorite breakfast) stuffing their house keys into their book bag.

Senku had already began walking to the stairs, (Y/n) trotting to catch up.

"Today we finally finish the compound hormone analysis." He declared, looking up to the sky with a fond smirk.

(Y/n) nodded in acknowledgment, swallowing the last of their breakfast.

The two walked to school, arriving 45 minutes early so Senku could squeeze in more studies in the school laboratory.

Senku began his studies as soon as they arrived, leaving (Y/n) to work on unfinished homework while fetching items he'd ask for.

(Y/n) and Senku had been friends since childhood. Their dynamic was one of leader and assistant. Senku would typically dictate what they were to work on each day, with (Y/n) keeping practical things in mind, like going to class, eating lunch, and taking breaks.

Senku had gotten used to having a lab assistant over time, including (Y/n) in all his plans. It was second nature to both of them to expect the other to be there with them in any given situation.

"(Y/n)," Senku suddenly spoke, "Do you know what day it is?" He pushed back his goggles, running a hand through his hair.

"Hmm.." (Y/n) tapped their chin in thought, leaning on an elbow on a table across from the table Senku used.

"Dunno."

Senku picked a small vile in front of him and held it up in the sunlight, "Today's the day we profit from the world's first love-inducing aphrodisiac!"

"Nihihihi~"

"Kukukuku~"

The two laughed sinisterly, causing students that had planned on entering the room to quickly rush by in fear.

"Now, we'll need a suitable test subject." Senku thought out loud, "Taiju is usually my test dummy, but his feelings for Yuzuriha nullifies his use as a control subject..."

"And Yuzuriha can't be used for that same reason." (Y/n) chimed in, mimicking the thinking gesture of Senku, "We need someone we know is objectively indifferent- someone who has no romantic interests at the moment..."

"Hmm..."

"What about your dad?"

"That's not a side of him I ever plan on seeing, (Y/n)," Senku answered, a deadpan expression matching his uninterested tone.

"Well my parents aren't an option," (Y/n) said, knowing Senku had already acknowledged their independent living situation.

Senku sighed, "Well, I guess we have no choice." Senku held up the vile to (Y/n), "Drink this."

"Hell no!" (Y/n) waved their hands in front of them, leaning back to bring more space between the vile and their mouth. "Besides, I'm not a viable candidate either!"

"Huh?" Senku picked at his ear with his pinky, a bad habit of his, "What do you mean? You don't have any romantic biases; as my lab assistant you should know you're also my back up guinea pig." He stated nonchalantly.

"But I do!" (Y/n) exclaimed bluntly, seemingly neither embarrassed or hesitant.

"You wHAT???" Senku suddenly yelled, completely subverting his disinterested demeanor beforehand.

(Y/n) uncovered their ears, "I do, so find a different test dummy!" They huffed.

Senku seemed like he was about to inquire on the subject, but quickly closed his mouth, revisiting his train of thought: Who can be used as a control subject?

"Well, looks like it's come down to this."

"Huh?"

(Y/n) yelped in shock as Senku downed the whole vile of substance with a gulp.

"You can't be the test subject!"

"We don't have any better options. I'll fill you in on how the agent works and how to note any findings." Senku explained, opening up notebooks as (Y/n) moved to stand next to him.

"The substance works as an extremely potent aphrodisiac. We'll call it-"

"The love potion." (Y/n) interjected in seriousness.

Senku rolled his eyes, "We'll call it the love potion for simplicity's sake. It works by flooding hormones responsible for rest, joy, and desire to the brain. This effect should only work in regards to one person; the potion will active whenever the subject's love interest is in mind.

"Your job, (Y/n), is to document all findings. Determine if the potion is working properly, and take lots of notes. The effects of the vial I took should last about a week, with results being visible within the first day."

"Gotcha. Hm, the first day, huh? Do you feel any changes then?" (Y/n) reached for a pen, pulling the notebook towards them and flipping to a new page.

"Mmm... no. Nothing noticeable yet. Also, I haven't figured out how to determine which person the potion with attach its effects to, so the first thing I'll..." Senku trailed off.

"Senku?" (Y/n) questioned, concern barely audible in their tone.

Senku's eyes were glazed over in a hundred-yard stare. He then suddenly fell to his knees, clutching his chest through his shirt.

"Senku!" (Y/n) exclaimed, catching him by the waist before his knees could hit the hard tile of the laboratory floor.

Senku brought a hand up to run through his hair, (Y/n) sitting on their knees as they held him, supporting his back and waist as he shifted to sit on the floor.

"Even better than expected," Senku muttered with a smirk, "(Y/n)!"

"Quit yelling, I'm right here." (Y/n) commented.

"Mark the love potion's affect time as two minutes!" He exclaimed triumphantly as (Y/n) picked up the notebook and pen they had previously been holding.