The next morning, an email from Clitify hit Makoto's inbox at exactly ten o'clock. Its notification made a cheerful ping that sounded far too innocent for the amount of stress it induced.
From: Kenta (Clitify Hiring)
Subject: Coding Challenge: Waifu-OS Prototype
Makoto opened it, his heart thumping hard against his ribs as he read.
Dear Makoto-san,
I heard good things about you from Ayane. Your background and experience seem… unique. We like it!
For the technical assessment, we need you to build a prototype chat interface with natural Language Processing (NLP) integration and state management.
Your Goal: Create a chatbot that dynamically adjusts its "Personality Temperature" based on user input. It needs to shift from Hostile/Cold (Tsundere/Kuudere) to Affectionate/Obsessive (Dere/Yandere) based on a hidden Affection Meter.
Bonus points for Summary and Memory modules that allow the bot to recall previous interactions and build a persistent emotional profile.
You have 48 hours. Good luck! Don't make it boring.
Makoto stared at the screen. Sentiment analysis was one thing, but capturing the actual feeling of a tsundere switch? That needed more than imported coding libraries. He would have had to understand the actual differences between pride and vulnerability, why someone would hide affection behind insults in the first place.
He leaned back and exhaled slowly. "Build a tsundere bot," he muttered at his IDE, the blank code editor glaring back at him. He needed data: raw, specific, high-fidelity data. Luckily, he was living with someone who had basically written the textbook on the subject.
Ten minutes later, Makoto found Yuna camped in the living room, surrounded by snack bags, the TV blasting the frantic sounds of a Minecraft boss fight. Yuna was hunched over her console with her gray hair shoved into a messy bun, wearing an oversized Gura shark hoodie with her bare legs tucked underneath her, hammering the controller buttons.
Makoto leaned against the doorframe, his phone in his pocket with the voice recorder already running. "Hey," he said, keeping it casual. "You're still stuck there, Yuna? Thought a pro would've cleared that yesterday. Getting slow with age?"
The clicking stopped, but Yuna didn't turn around. Her shoulders went rigid, and her shark hood twitched.
"What did you just say, fat pig?!" she shrieked, spinning around with her face bright red and her violet eyes sharp enough to cut glass. "Slow? I'm aiming for a no-hit run! You can't even reach the second boss and you're judging my control?"
She stood up and stomped over, jabbing a finger into his chest. "You're a distraction, pig bro. Just a loud, heavy waste of space. Why are you even here? Go stare at your stupid code before I delete your save files!"
Makoto watched her, cataloging the data: negative sentiment, high intensity, vocabulary focused on insults and ego protection, the trigger was a threat to her status. He noted her voice specifically, how she drew out "pig pro" and clipped the ends of her sentences when dismissing him.
"You're right," Makoto said, letting his voice drop. But he didn't back away. Instead, he reached out and put his hand on her shoulder. "I'm sorry. I know you've been working hard on this run. I was just jealous because I haven't seen your face all morning. I missed you."
The change happened instantly. Yuna froze, the anger in her eyes died, replaced by sudden embarrassment that turned her cheeks and the tips of her ears pink. She looked down at his hand, then back up at him, her lips trembling.
"I… uh…" she stammered, her voice soft now. She looked smaller somehow when she grabbed his shirt, her hands flustered while she avoided his gaze. "You can't just say things like that, idiot. It's gross."
She leaned her forehead against his chest. "I missed you, too, I guess," she whispered. "But only because no one brought me water. Don't let it go to your head, baka."
"Thanks," he said, kissing her forehead. "That was helpful. I got the data I need."
"Helpful?" She huffed but didn't pull away, just snuggled closer against him. "What are you talking about, big bro?" Then she went limp against him. She let out a long sigh, and her eyes fluttered shut.
"Yuna?" Makoto called out.
"Tired…" she mumbled, her voice slurred. "Everything is so dizzy. I get tired so easily lately. I need a nap, big bro, a long one." She paused the game and curled up, pulling the blanket over her head. "Don't wake me up unless the house is on fire."
She didn't make it back to the couch. She slid down his body until she was sitting on the floor, her head resting against his thigh. Seconds later, she was asleep, breathing deep and even.
Makoto watched her, frowning. Yuna never slept this early. She was a night creature, usually running on caffeine and spite. "Maybe she's getting sick," he thought. "Or maybe the stress of being the Main Wife was finally getting to her."
He grabbed a futon and draped it over her, bringing her onto the couch. He leaned closer to kiss her forehead, noticing her scent had changed. It was still sweet, but with something richer underneath that he couldn't identify.
He made a mental note to buy ginger ale tomorrow, just in case.
After making a cup of thick black coffee, he headed to the kitchen.
"Collecting data, darling?" Mika sat at the dining table with her laptop open. She was watching him, chin resting on her hand, her pink eyes tracking every movement.
"I need to build a yandere module too," Makoto admitted, sitting across from her. "The assignment didn't ask for it specifically, just a dere should be enough. But if I want to impress them, I should show I can handle the dangerous archetypes."
Mika's smile stayed the same, but the room felt colder. She reached out and traced the edge of his face. "Dangerous? I prefer devoted. A yandere isn't a monster, Makoto. She just understands the value of a man and takes steps to secure it."
She leaned forward, her voice dropping to a whisper. "If you want dialogue, I can provide it. But remember, a true yandere doesn't just threaten, she will follow up."
"Well, let's see," Makoto said, fingers ready on the keyboard. "Imagine I start talking to a cute gray-haired girl at work..."
Mika's eyes darkened, her pupils swelling.
"Oh? A girl at work?" Her voice went sweet and melodic. "That's lovely, darling. It's important to have friends. What was her name? Does she have a nice smile? I'd love to meet her."
Mika continued. "I've already checked the company directory and found three women who fit your description. I also cross-referenced their LinkedIn profiles and their social media accounts with your GPS logs from lunch. It's so much easier to be happy when there are no uncertainties in our relationship, don't you think?"
Makoto shivered as he typed. "That's perfect, Mika. But terrifying."
"It's not terrifying if you have nothing to hide, darling," she whispered, reaching across to take his hand. Her grip was tight. "A yandere bot will need a way to remind the user that she is always watching, always listening. Because she loves him, and because he is her."
She looked at him with a small smile. "You should make the bot remember every detail, every preference, every mistake. True love keeps perfect records."
"Thanks, Mika. That was... helpful." Makoto said, wiping sweat from his forehead.
"You're welcome, darling." She turned to the counter and opened a jar of pickled plums, then frowned. "These smell strong today."
She closed the lid and pushed the jar away. "I'm going to bed," she announced, walking past him. She paused to whisper, "Don't stay up too late, darling. I'll know if you do."
===
The sun had set hours ago, and the apartment was bathed in the blue-and-orange glow of Makoto's dual monitors. He was in the zone, that flow state he hadn't felt in weeks. The code was working now, a mix of Python and JavaScript working exactly the way he'd envisioned.
He had finished the first version of the chatbot. The transitions worked: If the user was cold, the bot snapped back with Yuna-style grumbles. If the user was kind, it gradually melted into a soft, needy dere state.
But the summary and memory modules were the real achievement. He'd built a small embedding database that stored emotional weights rather than just text strings. If a user mentioned liking a certain food, the bot associated that food with happiness and brought it up later to nurture them.
"Feel like I was coding Mafuyu's soul into themachine." Makoto sighed and took a short break.
Time flew fast. At 11 PM, Makoto made another commit and pushed the code to the Clitify repository. He was shaking with exhaustion, his eyes burning, his head full of nothing but syntax.
He walked into the living room to clear his head. Yuna was still there, sprawled on her stomach with her face buried in a pillow, her twintails sticking up in the air.
Makoto walked over to pick her up, then stopped. She looked peaceful, but different somehow. Her face looked fuller, softer around the jaw than it had two weeks ago.
He reached out and gently stroked her hair. Yuna didn't wake up. She just let out a soft, contented hum and snuggled deeper into the cushion.
Makoto pulled the blanket up and tucked it around Yuna's shoulders. She stirred, mumbling something unintelligible. "Pikachu…"
Makoto smiled and kissed her forehead. "Goodnight, my Main Wife," he whispered.
He checked his phone. One day left until the deadline. He had the code and the data. He had a reason not to fail.
He sat on the floor beside the couch, rested his head against the cushions, and for the first time in forty-eight hours, he let himself fall asleep.