I. Senku x Fem!mathematican!Reader x Kohaku
Summary : A case where kohaku has feelings for Senku, but he has feelings for you, and you have feelings for kohaku. A perfect love triangle…
Warning : Fluff, Angst ?, no good ending technically, Gen is tired of Senku, jealousy, miscommunication, humor, Senku is bad with his feelings,
The first person to notice something was wrong was probably Gen. And not because he was observant….Well, he was. But mostly because Senku suddenly started acting like an idiot. Which was rare enough to be concerning.
“Senku-chan…You’re staring again.”
Gen pointed dramatically across the village.
“I don’t know what you’re talking about.”
And across the village, you were helping Kohaku carry supplies. Nothing strange or weirdly suspicious. Just two people transporting wooden planks… which is normal, completely normal. Except the planks were light enough for Kohaku to carry fifty of them alone.
“Why is she helping?” Senku asked.
“Oh, so you WERE watching.”
“Dumbass, everyone can see them.”
Senku immediately hid the primitive binoculars.
“…scientific observation.”
The problem was that Senku himself had absolutely no idea what was happening. If somebody asked whether he admired you? The response was obvious…
You were one of the few people capable of keeping up with him intellectually.
Back before petrification, your papers had been among the few academic publications he’d genuinely enjoyed reading. After he saw your statues that he decided to use the last acid nitric to revive you, he’d spent three straight hours discussing mathematical models with you.
Three hours. Without getting bored. That alone should have been a warning sign.
Unfortunately, Senku Ishigami possessed the emotional intelligence of a brick whenever his own feelings were involved.
So every strange feeling got labeled:
You spending time with Kohaku? Scientific curiosity.
Feeling irritated whenever Kohaku monopolized your attention? Scientific curiosity.
Looking around the village for you before starting projects? Scientific curiosity.
Being able to immediately locate you in a crowd of one hundred people? Scientific curiosity.
And Gen wanted to hit him with a shovel.
Meanwhile, you had an entirely different problem…Your problem had blonde hair, and muscles. In fact lots of muscles..
Because yes, you had fallen for Kohaku months ago or maybe longer not that anyone cared about that. You weren’t even sure when it happened. Maybe it was one big moment ? Or dozens of little ones…
Kohaku carrying an injured villager for miles without complaint.
Kohaku standing between danger and people she loved.
Kohaku smiling after successful missions.
Kohaku asking questions about your work because she genuinely wanted to understand it.
That last one had been especially special to you has most people heard mathematics and immediately wanted to die.
Kohaku simply listened and actually listened…Even when she understood maybe ten percent of what you were saying.
“So if the equation predicts movement…”
“And movement predicts hunting routes…”
“And that helps us find animals?”
You had nearly proposed marriage on the spot. Unfortunately, Kohaku only saw a friend. A very important friend. A trusted friend. One of her favorite people.
Which was almost worse for you, because she genuinely liked spending time with you. You weren’t imagining that part.
Kohaku looked forward to your conversations. She sought you out and she even laughed more around you than around most people.
But whenever her eyes lit up the brightest…
It wasn’t because of you. It was because Senku had just walked into the room. And every single time, your heart sank..Not enough to stop loving her, just enough to hurt.
The funny thing was that Kohaku had her own frustrations too because from her perspective, things made absolutely no sense.
She knew she liked Senku. I mean that wasn’t exactly a secret….Maybe she hadn’t said it outright but everyone with functioning eyes could tell.
The problem was Senku itself. Specifically the way he acted around you.
One afternoon, Kohaku was helping transport materials for a new workshop and you were walking beside her, happily explaining some geometric trick you’d used to improve a bridge design. She was listening carefully (more like trying, really trying..)
“…and that’s why triangular supports distribute force better.”
You laughed and she actually laughed too. For a moment everything felt nice, easy, comfortable…
Then Senku appeared. Not dramatically. Not suspiciously. Just suddenly ?
Like he had spawned there.
“Important calculations.”
“Can I do them tomorrow?”
This discussion made Kohaku crossed her arms, still looking at both of them.
“Then tell us the calculation.”
Senku paused. For three whole seconds, like he was looking really fast for an answer.
The silence that followed was painful has even you looked unconvinced.
Kohaku watched the two of you walk away afterward. And she hated the strange feeling in her chest. Not because you were leaving. But because Senku had looked relieved when you agreed to go. And she couldn’t stop noticing things like that anymore.
The way his attention followed you. The way he listened more carefully when you spoke. The way he remembered random facts about you.Things he normally didn’t bother remembering.
One evening she made the mistake of mentioning it to Chrome.
“Does Senku always do that?”
Chrome immediately started choking on water.
And that was the end of the conversation. Because Chrome had enough survival instincts not to get involved.
The months passed. The triangle remained.
You kept finding excuses to spend time with Kohaku.
Kohaku kept finding excuses to spend time with Senku.
And Senku kept finding excuses to spend time with you.
And more time passes, more the excuses became increasingly ridiculous.
One day Senku interrupted your conversation with Kohaku because he urgently needed help calculating something.
The calculation was 2 + 2.
“Read it again, I need verification.”
Kohaku looked seconds away from throwing him into a river. The worst part? Senku wasn’t technically doing it consciously. That was what made it impossible to be angry. He genuinely didn’t understand why seeing you laugh with Kohaku made something twist painfully inside his chest….So his brain invented reasons.
Scientific reasons. Logical reasons. Reasons that became increasingly absurd.
Meanwhile, every time Kohaku looked at Senku, your heart broke a little.
And every time Senku looked at you, Kohaku’s heart broke a little.
And every time you looked at Kohaku, Senku felt that stupid twisting feeling again.
A loop so ridiculous that if any of them had taken one step back and looked at the whole picture, they probably would have screamed.
Instead they stayed exactly where they were. For instance three people sitting around the same campfire one night, just talking, laughing or existing together.
And none of them realized they were looking in three different directions. Even for the smartest man in the stone word, or for the best mathematician ever, or the strongest woman that her strong could be compared to a gorilla. Above them, the stars shone exactly always had. A lot like this stupid, hopeless, never-ending triangl for approximately ten seconds before sighing deeply.
“These people are never figuring it out.”
