The Shinobi world had only just entered its electrical age; even in the most prosperous village, Konoha, it was impossible for the streets to be brightly lit everywhere.
Over by the Hot Spring Street, foot traffic became exceedingly sparse late at night, rendering the entire area profoundly quiet.
Furthermore, Tsunade's small hot spring estate had virtually no immediate neighbors, making it even quieter after dark; usually, not even the bark of a stray dog could be heard.
With no visitors and highly regular sleeping schedules, the residents typically retired early.
However, on this particular night, the light in one specific room of the hot spring estate remained brightly lit until dawn.
On the bed, a young boy (shota) and a mature, voluptuous older woman (one-e-san/MILF) engaged in a night of wild, unrestrained passion. The process of the fully ripened woman transitioning from initial, fierce resistance to active, eager participation was undeniably tortuous and complex.
Smack! Smack! Smack!
The relatively small, slender boy was currently straddling the mature, voluptuous woman—who was a full head taller and significantly broader than him—driving his hips with relentless force. It was a perfect, literal demonstration of "a small horse pulling a massive cart."
The mature woman's long, pale, and incredibly thick thighs were wrapped tightly around the boy's waist like a vice. Her ten plump, perfectly rounded toes were curled tightly in a display of intense physical exertion. It genuinely looked as though if she squeezed those powerful thighs just a fraction harder, she might snap the boy's waist in half.
Her arms were wrapped tightly around the boy's head, pressing his face forcefully into her two massive "white rabbits"—which were nearly the size of his head—grinding him against them as if she were nursing him. The boy, working tirelessly, looked as though he were buried in a massive pile of incredibly soft, pale, and luscious cotton.
Judging purely by the massive disparity in their physical size, an observer would easily assume the older woman was bullying the boy. Yet, the boy's face was etched with a look of iron-willed, unyielding determination, while the voluptuous woman wore an expression of sheer, overwhelmed defeat, looking as though she might pass out from pleasure at any given second.
"Nngh... ah... slower..." her consciousness completely scrambled by lust, the mature woman responded purely on biological instinct.
The boy's expression was taut, his features rigid, but he too was rapidly approaching his absolute limit. After a final few, punishing thrusts, he wrapped his arms tightly around the woman's plump, pale body, shuddering violently before slowly collapsing limply on top of her.
"Ahhh!" As if finally granted a reprieve, the voluptuous woman's body mirrored his violent shudders before her fully ripened frame also went completely limp. A look of profound, utter satisfaction spread across her flushed face as she drifted into a deep, exhausted sleep.
Sprawled on top of the mature woman, the boy gasped heavily for air. It took him several long moments to finally catch his breath. Like a spoiled child, he nuzzled his cheek affectionately against one of her soft, pale "white rabbits" before reluctantly lifting his head. The woman, her face a portrait of exhaustion mixed with deep satisfaction, was already fast asleep.
Looking at her sweet, sated sleeping face and listening to her soft, rhythmic snoring, Saiki whispered softly, "Sister Tsunade?"
Naturally, the thoroughly satisfied and deeply asleep Tsunade didn't hear him. Saiki whispered her name two more times just to be absolutely certain she was completely out.
Gently removing Tsunade's hands from his head, Saiki slowly pushed himself up. He couldn't help but find the situation slightly amusing; he hadn't expected Tsunade to maintain such a vice-like grip on his waist with her thick, powerful thighs even after passing out.
Extending his hand and drawing upon the Pre-natal Qi within him, Saiki tapped a specific pressure point on Tsunade's lower abdomen, ensuring she was completely, deeply unconscious. Only then did he manage to pry her thick thighs off his waist.
Rubbing his sore lower back, Saiki wasn't entirely sure if the ache was from Tsunade's crushing leg-lock or simply from excessive energy expenditure.
Looking at Tsunade—sprawled out in a totally uninhibited, star-fish posture, her pale, thick thighs spread wide open—Saiki couldn't suppress a fond smile. He genuinely found the current Tsunade incredibly endearing, and he felt an overwhelming, profound sense of happiness.
Grabbing Tsunade's knees, Saiki slowly pulled himself backward. With a loud POP—sounding exactly like a radish being yanked from a muddy hole—they separated. The overstretched "spring" remained gaping open for a long time, unable to immediately close.
With every rise and fall of Tsunade's chest and abdomen as she breathed, a wet squelch echoed as the accumulated spring water and his essence, no longer plugged, suddenly gushed out.
He looked at the chaotic state of the bed. The quilt had long since been kicked to the foot of the mattress, and the sheets were covered in the messy evidence of their union.
Tsunade's obscenely voluptuous figure was a clear indicator of her "fertility." The pristine white bedsheets were stained everywhere with various "maps" drawn by the fluids that had leaked from her body.
Grabbing the tissue box from the nightstand, Saiki began cleaning up the mess for both of them.
After wiping the glistening, sticky strings from Tsunade's lips, Saiki gently pressed down on her lower abdomen. To his surprise, with a wet splat, another significant volume of clear essence spilled out.
Scratching the back of his head, Saiki realized he might have indulged a bit too much.
If he didn't clean her out properly, who knew if she might actually get pregnant? Saiki considered it for a moment, but ultimately decided against it. He couldn't take advantage of her while she was unconscious!
Coating his fingertips in Water Style chakra, he carefully reached inside, performing a thorough cleanse until he was satisfied everything was handled.
Having been relentlessly bullied by Saiki for who-knows-how-long, Tsunade, despite her incredible regenerative abilities, was still visibly red and swollen. Saiki had no choice but to use the Mystical Palm Technique to provide some immediate medical relief.
Getting out of bed, he walked over to the window and pulled the curtain back just a fraction of an inch.
"Is it almost dawn?" Looking at the pale light creeping over the horizon, then turning back to the deeply sleeping Tsunade, Saiki finally admitted that he had probably gone a bit overboard.
Closing the curtain, Saiki pulled a spare futon from the closet and laid it out on the floor. He gently lifted Tsunade from the bed and placed her on it. After stripping the ruined sheets and mattress protector—the casualties of their wild night—Saiki finally placed Tsunade back onto the freshly made bed.
Looking at Tsunade's alluringly curvaceous, mature, and voluptuous naked body, Saiki didn't immediately dress her; he had one final, crucial task to complete.
Saiki knew perfectly well that despite utilizing his dual cultivation ability to ruthlessly dominate her in the later stages of their encounter, the moment she woke up, Tsunade was going to hate his guts. Therefore, Saiki had to do something highly unethical.
First, this was necessary to create opportunities to further develop their relationship. Second, it was to prevent Tsunade from simply running away and disappearing forever. Given what had just transpired, Saiki knew Tsunade was absolutely capable of doing exactly that out of sheer shame.
Having positioned Tsunade comfortably, Saiki knelt beside her lower abdomen. After mentally organizing his thoughts, he began to weave a rapid sequence of hand signs. If anyone had been watching, they would have realized this was the most focused and serious Saiki had ever been while forming seals.
In a single, unbroken breath, Saiki wove exactly forty-nine signs to complete the complex formula.
The final sign was the Seal of the Tiger. This wasn't some Fire Style jutsu; it was a highly advanced Curse Mark!
Holding the Tiger seal with his left hand, Saiki extended the index and middle fingers of his right hand like a sword. He began tracing a curse pattern directly onto Tsunade's completely bare, hairless lower abdomen, right above the "inverted triangle" marking her Dantian.
He drew the pattern rapidly, as if he had rehearsed it in his mind countless times.
When he finished the continuous, unbroken stroke, Saiki channeled his Pre-natal Qi, tapping his fingers precisely in the center of Tsunade's lower abdomen. Infused with the Qi, the invisible curse pattern he had traced suddenly flared to life.
Activated by the Pre-natal Qi, the originally black lines of the curse mark shifted into a vibrant, glowing pink.
The Pre-natal Qi bifurcated into Yin and Yang energies, flowing seamlessly into the curse pathways. A heart-shaped pattern materialized on her skin. But it didn't stop there; the lines extended outward from the heart, eventually forming a pair of resplendent, stylized wings. The entire completed design resembled a winged heart, subtly mirroring the anatomical contours of a womb.
Finally, as Saiki withdrew his hand, a Yin-Yang symbol (Taijitu)—representing the perfect embrace of negative and positive energies—materialized in the very center of the heart.
Saiki hadn't even actively triggered the curse mark yet; merely having it inscribed on her skin caused the unconscious Tsunade's body to instinctively writhe, her legs rubbing together restlessly.
Drawing forth another wisp of Pre-natal Qi and injecting it into the curse mark, the glowing Taijitu finally faded back into her skin. Saiki let out a long, exhausted breath. Completing this specific Curse Mark jutsu had drained a significant amount of his energy.
This particular curse mark possessed several distinct functions. First, by weaving a specific sign, Saiki could activate the curse to completely paralyze Tsunade, stripping her of all capacity to resist.
Second, if Tsunade failed to seek him out within a month to have him inject a fresh surge of Pre-natal Qi or chakra to suppress the mark, it would trigger automatically. The Yin and Yang energies Saiki had stored within her body would violently erupt, plunging her into a state of agonizing, overwhelming lust. This effect was undeniably, profoundly wicked.
Third, while trapped in this state of overwhelming desire, Tsunade would also be subjected to a powerful Genjutsu, forcing her to constantly relive every single intimate, erotic moment they had shared in bed on an endless loop within her mind.
As long as Tsunade refused to seek him out for suppression, this effect was guaranteed to trigger sooner or later.
The fourth function was designed for Tsunade's protection. Saiki obviously didn't want Tsunade falling into that vulnerable state of lust while he wasn't around, risking her being taken advantage of by someone else. If any male approached her while she was trapped in that lustful state, the curse mark would instantly snap her out of her desires, plunging her into a violent "berserk" mode while significantly amplifying her physical strength.
His ability to create such a complex mechanism was largely thanks to the advanced Sealing Jutsu knowledge Kushina had taught him.
Saiki's decision to do this was highly calculated. He could guarantee that Tsunade wouldn't notice the mark under normal circumstances, and she certainly wouldn't notice it while consumed by lust. But the most crucial element making this possible was his unique Pre-natal Qi.
Following their dual cultivation session, upon waking, Saiki had discovered that the bottleneck he had been stuck at for years had finally shattered. The stubbornly stagnant Pre-natal Qi had finally evolved, bifurcating into pure Yin and Yang energies.
With this breakthrough in his cultivation, Saiki's mind had been flooded with new insights and understandings on how to manipulate this evolved power.
The curse mark Kushina had taught him fundamentally only provided a structural framework for sealing and storage!
The ability to induce and amplify Tsunade's lust, drag her into a Genjutsu, and boost her combat power when in danger—these were all direct effects of the Pre-natal Qi itself.
Furthermore, as the Pre-natal Qi passively circulated within Tsunade's body, it would continuously nourish and strengthen her physique.
Saiki's intentions were undeniably wicked and shameless, but he also genuinely loved Tsunade. Despite painstakingly cultivating his Qi for three agonizing years, Saiki had unhesitatingly transferred a full year's worth of that accumulated Pre-natal Qi directly into Tsunade.
The quality of this Pre-natal Qi was astronomically high. Saiki felt that this energy was virtually identical to the "spiritual Qi" described in Xianxia cultivation novels; as long as one stepped onto the Daoist path and condensed their Qi into a golden core, achieving longevity and near-immortality was entirely possible.
Compared to something like Six Paths Chakra, the qualitative purity of his Pre-natal Qi was leagues beyond.
Unfortunately, the sheer volume was pitifully small. Three years of relentless, backbreaking accumulation had yielded only a meager amount!
This energy would remain dormant within Tsunade. If she attempted to run away, Saiki could use it to suppress her; if she managed to escape, this energy would inevitably compel her to return to him.
Much like how Yin-Yang Release (Onmyoton) can nullify all Ninjutsu, the curse mark Saiki had placed on Tsunade was absolute. Even if Tsunade discovered it, the sheer qualitative disparity between their energies meant she was fundamentally incapable of breaking his seal. This was the dark, calculated method Saiki had devised to tame her.
It was incredibly wicked, completely shameless, and utterly lacking in basic decency. He was essentially planning to turn Tsunade into his personal plaything.
Saiki himself hadn't even realized it, but before engaging in dual cultivation with Tsunade, his feelings for her had been genuine affection. However, by utilizing dual cultivation as the catalyst to force his breakthrough into Yin and Yang, his mindset had unconsciously become much darker and more sinister.