35. Winter Means Hot Packs
Winter had come around again.
"Achoo!"
Seria, peering out the window, let out a little sneeze. It had only been a few days since she'd fully recovered from her cold, but the chilly wind still turned the tip of her nose faintly red, which bugged me to no end.
'The world outside the blanket is dangerous.' That's a universal truth. But you can't exactly spend your whole life huddled under the covers, right?
And seeing Seria suffer like last time just breaks my heart.
"Nope, can't have that."
What comes to mind when you think of winter? A heater? Yeah, that'd flop hard on sight, so pass. A stove? We've got a wood-burning one in the living room, but no electric ones here.
"Honestly, inside the house is fine enough."
I needed something to keep her warm outside. So, clothing? Hats? Ear muffs? Fur gloves? Fur boots? Truth be told, what she's wearing now isn't half bad. Dad's been splurging lately with all the money rolling in—everything's top-grade now.
"Oh!"
It hit me right then. Hot packs! Nothing fancy, but super effective.
"Perfect, that's it!"
I plopped down at my desk and dug out a few low-grade Mana Stones from the back of the drawer.
The goal was simple: Make a portable hot pack so Seria could stay toasty even outdoors.
I started carving a basic fire magic rune onto the Mana Stone's surface with a fine engraving tool. The trick was to keep the flames vibrating inside the stone, releasing only heat—no external fire. Then, applying the bimetal principle, I meticulously etched a circuit that physically blocks mana flow if the temperature hits 45 degrees.
"Phew, all carved."
Finally, I wrapped it in soft sheepskin I'd gotten from Head Maid and stitched it up tight with sturdy silk thread. A small embroidered Blue Rose—the Martel family crest—on the pouch finished it off.
"Hmm, the stitching's a bit wonky, but it'll do."
There, in my palm, sat the adorable leather pouch. I christened it the "Magic Hot Pack Mark-1."
Grinning triumphantly, I scooped it up and stood.
"Seria! Come here!"
She approached from the corner where she'd been polishing her sword, her eyes locking onto the pouch in my hand.
"What'd you make this time, Young Master?"
"Behold, the 'Magic Hot Pack Mark-1'!"
"······Mark-1?"
Seria's face froze solid. Oh crap, should've skipped the "Mark-1."
"No way!! I'm not riding it!! I'm not using it!!"
"Wait, this one's not dangerous! For real!"
I grabbed her as she backed away in panic.
"You caught that cold last time, remember? This is a portable heater I made special so your hands don't freeze this winter. See, there's a Mana Stone inside with a weak fire rune carved on it."
"······It really just gets warm? No sudden explosions or flying off?"
"What, you think I'm an assassin? Here, stick it in your pocket. I'll send a bit of mana through it."
Seria still looked skeptical, but my "I made it for you" line softened her up. She gingerly slipped it into her pants pocket.
"Activating now."
I snapped my fingers to trigger the rune.
Bzzz.
The stone vibrated faintly, starting to generate heat.
"Whoa······."
Seria's eyes went wide.
"It's really warm, Young Master. My pocket feels like a stove—wait, huh?"
Before she could finish—
Sizzle.
"Huh? Smell something like meat grilling?"
I sniffed around, and Seria slowly looked down at her pocket. White smoke was billowing out.
"Y-Young Master."
Her voice trembled.
"It's not just warm—it's hot. Like, my thigh's about to burn off."
"Wha—wait! What's wrong with the output control?!"
Whoosh!
Flames erupted from her uniform pocket.
"Kyaaah!! Fire! It's on fire!!"
"Uwaaah! Take it out! Throw it!!"
"Too hot to touch!!"
My room turned into chaos in seconds. Seria hopped around clutching her burning thigh, while I frantically gathered water magic.
'Whoa, Water Ball!!'
Splash!
My water bomb nailed her lower half perfectly. The flames hissed out, but Seria stood there drenched from the waist down, staring blankly. A huge, charred hole gaped in her uniform pocket.
"······."
"······."
Silence.
I averted my eyes and cleared my throat awkwardly.
"Ahem. Well, prototypes always have kinks, right?"
Shing.
Seria silently drew her wooden training sword.
"Young Master."
"Y-yeah, Seria? Let's talk this out, calm down."
"My reasonable suspicion that you're trying to assassinate me just turned into certainty. Today's training: twenty laps around the training ground."
"Aaaah! My bad! I'll redo the circuits!!"
"Stand still!!"
I crouched to bolt—then froze.
'Huh?'
Seria's lower half, soaked from my Water Ball, clung transparently to her skin. Through the wet white fabric······ very faint pink lace patterns shone clearly.
'Oh man, damn.'
I needed to run, but my eyes glued to those curves and colors. Our Seria wears that kind of cute underwear?
"Young Master?"
She tilted her head, like 'Why aren't you running?'
Then she realized where I was staring, slowly looking down at her soaked clothes.
One second later—
Psssh!
Her face heated up hotter than my hot pack.
"P-Per-Pervy Young Maaaster!!!"
She slapped her hands over her wet lower half and shrieked.
"N-No! I didn't mean to look! It just entered my field of view while putting out the fire!"
"Where are you staring like that?! Close your eyes!!"
Shing!
She drew her wooden sword again, face beet red, a menacing aura flickering behind her.
"I-It's a misunderstanding! And the pink suits you gree—gah!"
"Training's a hundred laps today!! Don't expect to come back alive!!"
"Aaaah! I'm sorry!! Mercy!!"
—One hour later.
Tears and snot streaming, covered in dust, I'd completely overhauled the Mana Stone's circuits. Triple safety locks, carved like mad to ensure it never exceeded 45 degrees.
"There, perfect now. Zero explosion risk."
Seria, changed into dry clothes, still glared daggers, but when it gave off only pleasant warmth without igniting, her expression softened.
"······Yeah, the temperature's just right. Feels like my hands are melting."
"Told ya. Genius inventor, remember?"
To test the finished Magic Hot Pack, we strolled out to the castle courtyard.
The early winter winds howled, but Seria walked calmly, hands buried in her coat pockets.
Me? "Ugh, freezing. My hands are numb."
I huffed hot breath on them. I'd rushed to make hers and skipped mine. No gloves either—my fingers felt like icicles.
"You should've worn gloves."
She glanced back, worried.
"Didn't think early winter would hit this hard. Should've made an extra."
I grumbled, shoving my hands in my pockets.
"Young Master."
Seria sidled right up. She opened her right coat pocket—the one with the hot pack.
"Give me your hand."
"Huh? Nah, I'm fine······."
"Hurry. You'll get frostbite."
Hesitating, I slipped my right hand into her pocket.
"Whoa······."
Toasty from the hot pack. But kinda embarrassing. Isn't this what couples do to make others jealous?
"It's cramped······."
I mumbled sheepishly, and her fingers intertwined with mine over my hand.
"No choice. Only one hot pack."
She sounded nonchalant, but her cheeks flushed peach-pink.
And so, hands crammed in one tiny pocket, shoulders brushing, we walked the courtyard. Each step made our fingers brush, tangle, touch again. Electric tingles shot from my fingertips, tickling my heart.
"Seria."
"Yeah."
"I made it, but damn, this hot pack's good. Hands might sweat."
She pinched my hand inside the pocket at my teasing.
"Hmph, shut up and walk."
"Ow! Hey, still mad? About the panty thing? Fine, I'll take mine off too."
I grabbed my waistband with my free hand.
"Wh-Wh-What are you doing!!"
"Oh, not this?"
"Pervy Young Master!!!"
Thwack! Thwack!
"Aaaah!!"
Even amid the banter, our hands never let go. In the biting early winter winds of the north, just holding hands like this kept the cold at bay.