Disclaimer: I own nothing, but my original characters.

AN: Be prepared for a long time-jump!

#Growth of Paradise in a Century!

"...ro...wake up! WAKE UP!"

I woke up with a jolt when something slammed my stomach. I swept away forced my sleepiness and focused on the extra weight on my stomach.

"Finally! You're up, bro!"

I blinked my eyes when I saw Isako sitting astride on top of my stomach. "Got off! You're heavy!" I tried to shoo her away since I still felt lazy to start the day properly.

"How rude!" She hit my bare chest with her fist. It had been a cute gesture when she was still a kid. Now, though, she had grown up and wasn't a little girl anymore. Well, she looked sexy and ravishing as a young buxom woman. She had grown up well.

I eyed her in a mix of annoyance and nostalgia. I then caught Isako's slender wrists to stop her harmless punches.

She pouted sexily before stealing a quick kiss on my lips. She then smiled impishly and said, "Now, you got your good morning kiss from your adorable little sister! So, rise and shine sleepy head!"

I rolled my eyes at her childish antics, pushed my body up, and toppled her curvaceous figure. I then gave her a brutal tickling without warning. My ambush made her gasp and try to stop me. Her body had crumbled back, giving me easy access to her. I exchanged our position. Now, I sat astride on top of her while tickling the life out of her. Unfortunately for her, she couldn't surpass my physical strength I boosted with my limitless and endless mana.

Before long, Isako had been turned into a heap of laughing fit. Tears were streaming down her smooth, unblemished cheeks, from her twinkling light brown eyes. Her skin was flushing red.

"Big bro...hahahaha...I surrend—hahahahaha...please...it hurts...hahaha...I'm sorry...I swear I won't do it any mo—ahaha...hahaha...haah!" She breathed in and out deeply when I finally stopped my tickling barrage.

She was sweating from her futile effort to free herself from me. Her outfit, which was a kimono with colorful flower embroideries, was rumpled. Her flowing brown hair had become tousled. Added in her heaving and sweaty appearance, one would misunderstand we had done something lewd. The sharp, musky smell permeated in the air just added the fuel for the misunderstanding.

But, I disregarded those meaningless thoughts and stared at the mischievous young woman pointedly. I said, "I have lost count how many you promised that. But, look! You keep doing this over and over again."

Isako averted her gaze as she became flustered by the fact I pointed out. She forcefully returned her gaze to meet mine and pouted. "What's wrong with it? I'm your one and only adorable little sister! I have the privilege to do this much!" responded Isako petulantly.

"Whatever..." I responded back and shrugged my shoulders before moving away from her. I then climbed down the excessively wide bed.

"Big bro, where are you going to?" asked Isako as she raised her body and looked in my direction.

I didn't look back, keeping my gaze ahead towards my destination. "Bathroom. I stink and am in need of quick refreshment," I responded.

"Wait for me!" demanded Isako in a hurry. There was a sound of rustling fabric from behind, but I continued walking. "Let's have a bath together!" she exclaimed.

I stopped on my track, standing in the archway, and looked back. I saw Isako butt naked and heading towards me in a hurry.

When she undid her kimono like that, it was shown how developed her body was. The part where it should swell, swelled, and the part where it should shrink, shrunk. She had the figure that would give my supernatural slave-harem with a seductive body as a racial trait runs for their money.

I gave her a dull look and said, "You're not a child anymore."

Isako pouted harder and climbed down the bed. She ran after before stopping in front of me. She then punched my chest. Although her blow would create a hole when she punched normal people, I felt nothing but a soft tap. "Don't be a spoilsport. Anyway, I'll give you a back massage and scrub your back! How? I'm a nice little sister, am I not?"

I eyed her dubiously, found no hidden meaning behind her offer, and nodded slowly. "I guess...you can do it. Fine! Follow me!"

After I said that, I turned forwards and entered my bathroom. Isako quickly skipped after me, following behind me closely. She had a wide, triumphant smile from the insignificant success. We then entered the bathroom together.

###

"Uuuuumh... Yesssh... That's it! Harder, big bro! Umm... Harder!"

"Can you make it sounded less like we're doing a lewd thing?" I complained to my little sister who was in bliss.

Unlike what you have expected from the lewd sounding voice Isako had made, we weren't doing something lewd. I was giving her an innocent massage while scrubbing her back.

Currently, we were submerging our body in the bathtub. The water temperature was high, but it was not hot enough to boil us. Well, calling it bathtub would be an understatement, though. It was as big as an Olympic swimming pool. The pool was built using pure white ivory. The bathroom was shaped like an octagon with eight tall walls and dome ceiling overhead. The whole room colored white, albeit with some murals on the walls with the image of different positions of sex.

When I looked at those murals, it made me question my past self as to why I did something so stupid like that.

Engraving nature scenery or other proper images would have been better, but no! The past me had my head stuck in the gutter at all times, making the murals of my bathroom filled with sex position that would give Kamasutra run for its money.

Doing lewd things was refreshing, but doing it excessively would make it boring quickly. In fact, I had lost a bit of my fervor for sex. I guess that would happen when you spent your free time in the span of several decades with nothing but sex.

Fortunately, I still had my fire for other lewd things such as groping, kissing, and naked-cuddling. But, I digress.

"Now! It's my turn," I said as I finished scrubbing Isako's smooth back. As a matter of fact, I could easily clean her back with a spell, but doing it like this was also a nice change of pace.

Isako looked back, eyeing me from the corner of her eyes. She was pouting.

"No way! Nope! You haven't cleaned everything!" She then turned her body around, showing off her ample breasts with a stiff pink nipple on each peak. "Rub my front too!" She whined childishly.

I gave her an unamused look and flicked her forehead. The strength in that flick would separate the heads of high-class devils and those equal in power from their shoulders. Yet, her head was still attached on her shoulders. Her only reaction was a soft "Owwie!" as she rubbed her reddening forehead.

Ignoring her cutesy gesture, I said, "I'm not in the mood for that. Let's just clean our bodies without doing something lewd. Got it?"

Isako gasped and covered her mouth in an exaggerated way. She then pointed her finger rudely at me and said, "Who are you? Where you hide my big brother? How can you—ouch!"

I flicked her forehead again. This time I did it harder, with a strength that would behead ultimate class-devil or those with equal power. I then said, "I really am in no mood for your jokes. For the past several days, I was busy giving," I quoted in the air, "blessing." I paused for a moment and sighed deeply. I then continued, "Can you imagine it?! Having sex days and nights with dozens of shy virgins? It's very mentally exhausting, I tell you!"

At that, Isako sent an unveiled amused gaze. I groaned and complained, "That's why I like to have sex with a more experienced woman, than a virgin. It was such a chore!" I then submerged myself until my eyes left outside of the warm water. Bubbles surfaced in front of my face.

Looking at me, Isako's pink lips curved into a refreshing smile. She then said, "Whose fault it is?"

I glared at her accusingly. Without saying it loudly, I realized it was my fault or my past self to be exact. My past self was really a moron whose head always stuck in the gutter.

Why did I think for having the eighteen years old girl offering their chastity for my blessing is a good thing? I could just grant power to them without having sex. Alas, it had become a deeply rooted tradition, and abolishing that practice would give a shock to my slave-harem.

Speaking of my slave-harem, in the span of a century, they had multiplied without an end. I started with less than five hundred heads of mixed races women a century ago. At this point, the total headcount surpassed four digits. To be precise, the numbers of Paradise's denizens were 12,876 women.

I'm the only male in this world.

How those women gave birth to the female baby, you ask? Well, I had installed my own system, after recreating the same System created and used by the late God in the Bible. That was why angels didn't fall even though they had sex with me, or committing Yuri.

What do you think? This place lacked the supply of testosterone and they could only seek the same gender to scratch their itches. It was impossible for me to properly satisfy twelve thousand women at all times! I had my own life, damn it!

The system was also the reason why only female babies were born.

From those numbers, around 3,000 were devils. Then, there were around 4,500 immortal human, 400-ish angels, 800-ish fallen angels, 300-ish Valkyries, and finally 3,400-ish mixed youkai (a mix between 652 Youko, 857 Nekoshou, and 2,000-ish Nekomata).

And let me tell you how Youko, Nekoshou, and Nekomata would give birth to more than a single baby. They just like the animal they were based on. It was rare for adult Youkou and Nekoshou to deliver only a single baby.

I had a hypothesis as to why Yasaka could only give birth to a single daughter in the past. And it related to her status as the center of Kyoto's leylines. Still, it also made Kunou had nine-tails the moment she was born. Any normal Youko started with a single tail, after all. Nekoshou, meanwhile, was born with two tails. The cat youkai with a single line when they were born was considered as Nekomata.

Huh, my knowledge about Youkou, Nekoshou, and Nekomata had grown up significantly in the past century.

In a related note, Paradise had grown significantly. Other than the first continent I made, other smaller continent also existed. I had created them and gave them to my slave-harem as their territory.

At this point, there were fifteen flying continents in total, with the one Ivory Castle stood upon as the core of this small realm.

Each race had their own territories, and yes, I split their living environments according to their races.

For the detailed information of these territories' infrastructure will be discussed in another time.

Next...

The women who had made their appearance in Highschool DxD anime, and some special individuals were adopted into Divine Royal Family and lived together with me in Ivory Castle. They were called Divine Concubines, ninety-nine in total.

My biased decision made the other women jealous, and to give them a chance to join Divine Royal family of Paradise, there would be annual Fighting Festival every four years. If someone could win against a Divine Concubine, the winner would replace the defeated Divine Concubine's position.

Other than the ninety-nine Divine Concubines, there were nine Empresses. The positions of each empress were indisputable and non-changeable. Those nine empresses were:

Empress of Angels: Gabriel

Empress of Fallen Angels: Penemue

Empress of Youkos: Yasaka

Empress of Nekomatas: Kuroka

Empress of Devils: Venelana

Empress of Valkyries: Rossweisse

Empress of Witches: Lavinia Reni

Empress of Dragons: Ddraig

However, because she was outside of Paradise, no one but Lavinia and Penemue had seen her.

And the last empress was Empress of Immortal Humans: Isako, my own sister.

As you expect, my relationship with Isako wasn't platonic, at all. It was shown in our interaction that was beyond the healthy relationship between two blood-related siblings.

I had groomed her as my lover when she grew up. And I was satisfied with the fruit of my patience.

"Anyway, it's your turn to scrub my back!" I demanded after pulling out my body from the water. I then turned around and displayed my unguarded back towards Isako.

"Sure!" Isako decided to drop her teasing and began to scrub my back. But…

"Use the scrubber you sexy sister of mine!"

I moved my body away from hers when I felt a pair of soft, elastic breasts being pressed on my back. The twin perking nipples were scrapping my skin.

"Awww!" Isako whined loudly before following my demand. She then scrubbed my back and gave me a back rub for real, without any lewd content if I must add.

For a while, we enjoyed the comfortable silence between us.

It was broken when Isako opened her mouth out of the blue.

"Anyway, Aunty Yasaka, Big Sis Kuroka, Big Sis Shirone, and Big Sis Kunou are going to give birth to their latest batch of children," she informed me.

"When?"

"In two months, I suppose."

"…I see." I paused and thought about something. Several seconds later, I continued, "Is that why you returned back to Ivory Castle yesterday?"

"Yup!" I heard Isako's quick answer.

For several months, Isako had been staying at Youkai Palace, the combined home of the ruler of Youko and Nekomata. The palace reminded me of Himeji castle in Japan, albeit bigger and grander. The place was standing atop a small floating island on top of the Land of Youkai.

The youkai lived together in a single land with two official rulers, but of course, Yasaka was the only one doing her job. Meanwhile, Kuroka was Kuroka.

Of course, the four of them had their places in Ivory castle for Yasaka and Kuroka are Empresses, meanwhile, both of Kunou and Shirone are my high-level concubines with the rank above fifty.

Some powerful Youko and Nekoshou lived in Ivory Castle, keeping the order in Land of Youkai as autonomous bodies of Yasaka.

Back to the story!

Since I didn't want to deal with their pregnancy's mood swings, I had shipped them towards their second dwelling. Usually, the four of them lived in Ivory Castle together with me and Isako.

Isako had followed them when I shipped them towards Youkai Palace. She had been in there for the past five months.

"I'll check them, later," I informed her calmly.

"Alright…I'll them later. They will feel happy when they know about this," said Isako as she stopped giving me a back rub.

Suddenly, Isako's hands slipped towards my crotch, she then began massaging my ramrod dick. What? I was a man in the end, and it was hard not to be aroused when I was alone with a pretty buxom young woman.

"Isako! Wait!" I tried to stop her half-heartedly. I wasn't in the mood for lewd activity, but my biological reaction betrayed me.

"What? Look! Your dick has become this hard! Be honest with your desire, Ne, Oni-sama." Isako had pushed her front on my back before she whispered that seductive words. She then blew her breath into my ear teasingly.

My body shivered at that.

She then slowly moved her body, up and down, while giving me a skilled handjob. Her squishy breasts were rubbing on my back, her stiff nipple scrapping my skin. It was very stimulating.

"…I missed you so much." She suddenly said. Her breath became irregular, rapid, ragged, and short. She had become aroused. "Five months without…my beloved big brother… How, agonizing… I can't imagine the agony of my aunties, big sisters, and little sisters who have been deprived of your care… for years, or even decades… It must be maddening…"

Sigh! I sighed in resignation when I heard that. I had given up any rejection for Isako's blatant seduction. I knew her so well that I'd realized she was giving many signals since she had woken me up a while ago.

I peeled Isako's hands from my dick, moved my body slightly, and turned around, facing her. I saw my own sister's needy expression, fully aroused, telling me that she was ready for being screwed. Not for the first time, I realized how successful my programming of her as she grew up.

"Fine… Only one round… We will have only one round, before I need to do my own thing." I informed her with a tone that conveyed my final decision. "I'm going to be very busy today."

Nevertheless, Isako perked up, as if she heard her birthday and Christmas came early, at the same time. I suppose, it was an exaggeration for an analogy. But, it perfectly expressed how happy she was after hearing my decision.

"Then… what are you waiting for?" She pushed her body closer to mine, circled one of her slender arms around my neck, and clamped my waist with her supple thighs. Her face was before mine, so close that I could smell her arousing fragrance.

"Ne,Onii-sama! Onegaishimasu…" She whispered sultrily as she used her free hand to guide my ramrod dick into her pussy. I then grabbed her squishy butts, and then, with a grunt, I pushed her body down and thrust up my hips, making my ramrod dick penetrating her vice-like, pulsating honeypot.