"UWEEEK!"

  A loud cry rang out from inside a house built from thick wooden pnks. It was a simple yet comfortable home, nestled against the side of a small hill as if growing out of the earth itself. The portion of the hill connected to the house was a sheer vertical wall, while the opposite side sloped gently downward. The house blended seamlessly with its natural surroundings.

  When the sisters arrived home, Homo Sapiens immediately handed the baby boy to her sister.

  "I have some experiments to run," she said. "Keep him entertained in the meantime, dear sister. But be gentle with him, or you might end up killing the fragile little thing."

  Homo Erectus awkwardly took the baby, holding him up in the air with both hands like a trophy.

  "If he cries, just let him suck on your tit or something," Sapiens added casually before turning away. She walked to the back of the house, opened a wooden door, and disappeared down a flight of stairs leading underground.

  Erectus was left standing there, still holding the baby aloft. "Okay…?" she muttered, uncertain. But as soon as she met Serakuza’s big round eyes, her doubts melted away. Once again, she was smitten with his adorable little face.

  ---------------------------

  Meanwhile, below the house, Homo Sapiens had entered what looked like an underground cavern. A space like this should have been damp and pitch dark, but instead, it was softly illuminated. No torches, no mps—only the natural glow of the moss covering the walls and ceiling, a product of Sapiens' own alchemical genius. She had cultivated a unique strain of bioluminescent moss, filling the cave with a dim yet sufficient light.

  The temperature remained at a constant, comfortable level, thanks to her mastery of wind magic.

  Stepping over to her worktable, she selected a few ingredients and began preparing for her test research.

  ---------------------------

  Upstairs, Homo Erectus was still holding Serakuza in the air, spinning around pyfully. The baby ughed in delight. But soon, his giggles turned into wails.

  "Ah, what do I do?" Erectus panicked, rocking the baby in her arms. "Did you get bored? Was that not fun anymore?"

  Serakuza only responded with louder cries.

  Erectus bit her lip. She adjusted her grip, holding the baby with one arm while using the other to pull open the front of her simple robe, exposing her bare breast. The moment Serakuza saw it, his cries stopped. His tiny hands reached out, instinctively drawn to the soft, warm mound.

  "Yeah, you want this?" Erectus cooed. She cradled him closer, pressing his face against her chest. Serakuza immediately tched onto her nipple and began suckling.

  "Oh… oh~" A strange sensation spread through her body. It felt… nice? She shivered slightly, an unfamiliar warmth washing over her.

  Then, without warning, Serakuza broke the tch and started crying again.

  "Huh?! Why are you crying now?!" Erectus excimed, flustered. She tried pushing him back to her breast, but he refused, his wails only growing louder.

  She groaned in frustration. Then, an idea struck her. She set Serakuza back into his basket, pulled open her robe completely, and pyfully jiggled both breasts in front of him.

  "There, you like this, don’tcha?"

  Serakuza let out a delighted giggle, momentarily distracted.

  Erectus sighed and cast a desperate gnce toward the door her sister had disappeared through. "Sis, hurry up…"

  ---------------------------

  Down in the cavern, Homo Sapiens was fully absorbed in her experiments. Her worktable was cluttered with gss beakers and test tubes, many filled with colorful, bubbling liquids. She lifted a particur tube containing a dark, fishy-smelling substance and frowned.

  "Another failure," she muttered. But she wasn’t discouraged—she simply moved on to the next attempt.

  Moments ter, frantic footsteps echoed down the stairs. Homo Erectus burst into the room, carrying Serakuza in his basket. His cries were deafening.

  "Sis~, are you still not done yet? I don’t think I can hold on much longer!" she whined.

  Sapiens barely spared her a gnce before returning to her work. "Did you try nursing him?"

  "I did! But he’s still crying!"

  Erectus pced the basket on an empty corner of the table, careful not to disturb her sister’s experiments. She crossed her arms, clearly exasperated. "What’s wrong with this boy?"

  "He’s hungry," Sapiens answered matter-of-factly.

  Erectus blinked. "That’s it? Hah! Then I guess I’ll just feed him some of that worm I caught earlier."

  "No, you idiot," Sapiens snapped. "He needs milk."

  "Milk? Where are we supposed to get milk?"

  "That," Sapiens said, her tone cool and unbothered, "is exactly what I’m trying to solve."

  Erectus gave a bnk nod. "Oh~."

  Serakuza's cries continued, echoing through the cavern.

  "Try to distract him a little longer," Sapiens requested, her focus unwavering.

  Erectus groaned. "I'll try. But I doubt it’ll work…"

  Time passed, filled with the baby’s relentless wails. Then, suddenly—

  "This is it!" Sapiens announced triumphantly.

  In her hand, she held a gss tube filled with a milky-white substance. A pleasant, sweet aroma wafted from it. Without hesitation, she tilted her head back and downed the liquid in one gulp.

  For a moment, nothing happened.

  Then, she hunched forward, hugging herself tightly. A low whimper escaped her lips.

  "Sis? Are you okay?" Erectus asked, concerned.

  Sapiens let out a soft, sultry moan, her body arching slightly. Then, she gasped as warmth spread through her chest—followed by a sudden, unexpected sensation.

  Her breasts swelled, her nipples tingled, and with a sharp jolt, a stream of warm milk spurted from both. It soaked through her clothes, creating damp, translucent patches over her pale skin.

  "Ah~" she exhaled, cheeks flushing bright red. "This is it… It worked."

  Erectus stared, eyes wide in shock.

  Sapiens composed herself and walked toward her sister, her wet robes clinging to her figure. Without a word, she took Serakuza into her arms, pulled open her clothes, and guided the baby to her breast.

  The moment Serakuza tched on and started drinking, his cries stopped. His tiny fingers curled against her skin as he suckled hungrily, his body rexing into hers.

  Erectus watched the scene in silence. Her gaze slowly shifted from Serakuza’s satisfied expression… to her sister’s other, still-leaking breast.

  A mischievous glint fshed in her eyes. She raised a finger to her lips in thought, then slyly asked, "Can I have some too?"

  "No," Sapiens deadpanned, not even looking at her.

  "Aww~," Erectus pouted in disappointment.

  ongsyukkura