Karinbana returned to the Investigators’ dormitory. Her room was a two-person suite shared with her master.

“Little Na’s back!”

The moment Karinbana opened the door, a confident, mature female voice filled the room.

Leaning against the headboard was a one-armed, one-eyed woman in a black tank top and an eyepatch. She flashed Karinbana a smile, then resumed fiddling with a rectangular metal slab using her only hand.

But this wasn’t ordinary metal—it glowed faintly.

If Roland were here, he’d shout: “Holy crap, is that actually a smartphone?!”

“Master, what is that?” Karinbana asked, slipping off her mithril armor to reveal a slender waist, long legs, and a perky silhouette.

Yet her chest…

Flat as a board.

She touched herself—completely smooth, not a hint of curve.

Even a washboard had texture…

She glanced at her master: voluptuous, commanding, a dream impossibly out of reach.

Karinbana let out a soft sigh, her expression dimming.

“This is the hot new ‘Arcane Device’—just a prototype. Only ten thousand units issued across the empire.”

Her master demonstrated it. After some fiddling, a chat window finally appeared.

“This is a group chat. Elves, dwarves—you name it. Cross-continent messaging, super convenient. The Arcanet founder? Seriously brilliant.”

With this, she could message comrades at the empire’s distant borders in seconds. Before, it took weeks. Long-distance arrays often failed.

“How’d you get one? Only ten thousand exist!” Karinbana asked.

“Your master sacrificed an arm and an eye for humanity. One word was all it took.”

Her master chuckled, typing in the Expeditionary Corps’ private group:

“Finally introducing my apprentice. Pretty face, great figure—too bad she’s a flat-chested tsundere.”

Replies flooded in:

“Big Sis! Missed you! How’s the injury?”

“Big Sis, send apprentice pics! Life’s been dull without your mischief.”

“Big Sis, I’ve got a secret remedy for flat chests! Guaranteed D-cup like yours!”

“Big Sis, flat-chested tsunderes are the best!”

Karinbana’s face darkened.

“Haha, don’t worry, disciple—I’ll ask about the remedy.”

“No! I won’t use shady methods!” Karinbana declared firmly. “My flat chest is from childhood malnutrition. Eat more, and it’ll grow!”

“Reeeally?” Her master smirked, glancing at Karinbana’s A-cup before puffing her own chest. *We both ate poorly. Why am I like this? Are you just… unlucky?*

“Eating more won’t help—it’ll just make you fat~”

“S-still better than shady tricks!”

“What if it *works*?” Her master narrowed her left eye, smiling slyly.

“W-well… I’ll try it! B-but not for me—just for you, Master!”

“Oho~” Her master slapped Karinbana’s shoulder, laughing, then read from the Arcane Device:

“Drink papaya milk three times daily. Massage before bed. Visible results in under a month.”

“No way,” Karinbana scoffed. “If massaging worked, I’d be bigger than you by now.”

“Maybe you skipped the papaya milk,” her master said confidently.

“Those things… so expensive…” Karinbana whimpered. Her hard-earned savings would vanish fast.

“True,” her master mused. “Marry a rich, handsome guy? Then you’d afford it.”

“But with a chest flatter than a washboard… tsk. Pretty face, great figure—but men love boobs. Zero appeal.” She jiggled her own chest.

Karinbana flushed crimson.

“I’ll work hard… and become the mother of a rich, handsome guy…” she murmured weakly.

“Admirable,” her master said gravely. “But you’re still naive, Na. Men say they love your heart—but really? Big boobs, round butt, long legs. You’ve got none of it.”

Karinbana glared at her flat chest, resentment thick in the air.

“And *you’re* still single, Master. At your age, you’ll be an old maid forever.”

Her master froze. Face darkened.

*Ouch. Right in the heart, disciple!*

*It’s not that no one wants me—I just won’t settle for weaklings!*

After a silent stare-down, her master powered off the Arcane Device, burrowed into bed, and turned away. “Sleep. Train tomorrow. You’ll break through to Martial Arts Level Five soon. Then I’ll teach you the next technique.”

Karinbana showered with a gloomy face. Returning, her master was already asleep.

The flat-chested Investigator hesitated, then pulled a milk bottle from the cabinet.

Truth was, she drank milk nightly and massaged her modest chest, hoping for even the tiniest swell by dawn.

No growth. Only lighter coins.

“Sigh…” She downed the milk, massaged as usual.

“Please grow soon…”

She whispered like a worried mother urging her child.

…

Night deepened.

In southern town, one house still glowed.

A junior mage, newly gifted a spellbook, read deep into the night.

“Daddy… nightmare,” a boy mumbled, rubbing his eyes.

“Go to Mommy. I’m busy,” the man said without looking up.

The boy left.

Later, a girl appeared. “Daddy… nightmare.”

“Go to Mommy,” he snapped, irritation rising.

She retreated.

Moments later, the pale-faced woman emerged with both children. “Husband… I had a nightmare too. Something’s outside…”

“Nothing’s out there! Sleep! We work tomorrow!” he yelled.

Trembling, she led the children away.

He sighed, turned the page.

Unseen, dark mist swallowed the house. Malevolent eyes watched. Sharp claws—carrying death itself—slipped inside.

Screams shattered the silence. Yet no neighbor heard a thing. The mist sealed all sound.

…

Dawn came. Karinbana, armored and composed, reported to headquarters.

Her mithril armor hid her flat chest. Few knew.

Her master still slept—exempt from duty as a wounded Expeditionary Corps veteran granted special privileges.

Karinbana often wondered about her past. All she’d ever said: “I retired from the Expeditionary Corps.” No rank. No strength level.

Yet Karinbana never doubted her. The stronger she grew, the deeper her master’s ocean-like power felt.

Lost in thought, she reached the hall—crowded with Investigators. Even the branch vice president stood there.

Karinbana quietly joined the group.

“Everyone’s here,” the vice president announced, glancing at her. His voice turned grave. “Last night, a murder occurred.”

“The Dem family of four in southern town was found brutally slain this morning.”

“This heinous crime threatens our town’s safety. We *will* find the culprit. We *will* restore peace.”