Inside the box, Nezuko began to undergo a remarkable transformation. Her childlike form of just 1'3''ft extended and expanded, inch by inch, until she reached 5ft, her teenage version. But unlike her usual appearance, her curves began to take on a fuller and more voluptuous shape, in harmony with the rest of her developing body.
"Uhh..." Nezuko couldn't help but moan with pleasure during the transformation. Even in her deep sleep, her body was wracked with excitement, and a fog of pleasure clouded her mind, leaving her intimacy increasingly wet.
As she neared her adult form of 5'7''ft, her clothes began to stretch to contain her transformation. Her kimono crept up her increasingly long and thick legs. The bands around her torso tightened, and the fabric seams yielded to the pressure of her growing breasts and expanding muscles.
As Nezuko continued to grow, the small bamboo box containing her began to feel increasingly tight. Her now longer and slender limbs pressed against the box's confines, while her developing curves encountered resistance on all sides. The space that was once sufficient for her diminutive form now felt suffocating, and instinctively, she curled uncomfortably to fit.
As she approached her adult form of 5'7''ft, her clothes struggled to contain this remarkable expansion. Her kimono, once loose and comfortable, now crept up her longer and thicker legs, while the bands encircling her torso tightened under the pressure of her growing breasts and firm muscles. The fabric gave way, seams creaked under the strain, and it was evident that her transformation was challenging not only the box but also her attire.
Every inch of growth was accompanied by an increasingly tight squeeze, as if the very box was trying to contain the force of the power manifesting within. Nezuko could feel the heat and pressure intensifying around her, making it increasingly difficult to breathe and move. Her now more pronounced and defined muscles were taut against confinement, and she longed for space to stretch and break free.
As Nezuko continued to grow, the weight of the transformation increased inside the box, leaving Tanjiro bewildered, not understanding what was happening.
"This doesn't make sense... why are you getting heavier, Nezuko?" Tanjiro wondered.
The box's center of gravity shifted, moving with his sister's growth, and Tanjiro began to feel the mounting pressure as he struggled to maintain balance in the dense forest.