How Using My Oppai Skill to Enlarge My Sister’s Breasts Led to Building a Harem

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Chapter 16

Miyabi, claiming it’s practice for “nighttime duties,” bares her hips before me.

“In the Saionji family, to prevent conceiving children outside, maids handle sexual desires.”

“Handle… with you, Miyabi-san?”

“If I’m undesirable, I can arrange another.”

“N-No way! It’s not that, it’s just…”

Miyabi’s beauty is otherworldly, rivaling even Ayaka’s.

And right now, her pale hips and private parts are exposed before me.

(Ugh… beautiful… such a perfect pussy…)

A sweet scent wafts from her, the prime pheromones of a woman in her mid-20s, luring me in.

“A man needs the ability to sire children and to please and bind the lady’s heart.”

“Are you… okay with this? With someone like me?”

“You, who’s seducing and stealing the Saionji daughter, say that?”

True. I’m taking Ayaka from her husband. I can’t falter now.

My crotch is already hard, my cock pushing against the thin yukata fabric.

“You seem ready. Impressive, still so vigorous after satisfying milady.”

It’s not that Ayaka wasn’t enough. Miyabi’s lewd display just ignited my arousal, churning out semen rapidly.

“Haa, haa… Miyabi-san…”

“Use my hole freely.”

I don’t want to treat a woman like an object. But the ripe, fruity scent from her peach-like hips defeats my reason.

Gugu… Gunyuuu♡

“…Nn… u…”

“Ku… tight… Miyabi-san, how much experience do you have…?”

Her hole’s so tight I thought she was a virgin.

“Don’t worry. I have no male experience, but I’ve trained with dildos.”

“Trained?”

“To always be ready to relieve my master’s desires.”

Is that okay for a woman? But right now, I need to thrust into this tight pussy.

“I’ll go a bit harder… Hn!”

Zubu Gugu, Nyuuu♡ Ton♡

“Nn… fuu…”

“I’m all the way in, Miyabi-san.”

“Yes, now release as much as you want into my hole.”

For her, this is just sexual relief, her pussy a tool for her master’s desires.

But I can’t accept that.

“I want you to enjoy this too, Miyabi-san.”

“Don’t jest…”

“Then I’ll make you feel good.”

Sex is for mutual pleasure, not one-sided. I love women, so I want them to be happy too.

I place my hands on her round hips, pierced by my cock, and focus my strength.

(I can do this. Her meridians aren’t open yet, but with my skill…!)

Guniuuu♡ Gunyu! Munyu!!

I press hard into the erogenous points on her hips, channeling energy from her tailbone up her spine to her breasts, spreading through her body.

Gyuuuu♡ (Go!)

“…Nn… —Nnn♡”

A sweet moan escapes her lips briefly. My palms feel her reaction.

“I’ll move my hips too.”

Nyuu♡ Pachin!

“…! …A”

Nyuu♡ Pachin!

“…! …U♡”

She’s feeling it. Her face stays calm, but my hands know better. Next, I target both her hips and pussy.

Gunyu♡ — Nyuu♡ Pachin!!

“Fuu…♡ Nn… Uu♡”

It worked. Her body reacts, her pussy tightening, kyun♡, around my cock.

“How’s that, Miyabi-san? Feels good, right?”

“What? I’m not feeling… anything.”

Her voice is a perfect mask, sounding unfazed.

But her body’s honest.

Nyuu♡ Pachin! Nyuu♡ Pachiiin! — Pachin♡ Pachin♡ Pachin♡

“Nn! Nnnu~~~! Fu, guuu♡”

“Amazing! Your pussy’s incredible, Miyabi-san!”

Her tight hole, crushing my cock, takes my relentless thrusts.

“Nn~~~! Nn…! …~~~U♡”

(Miyabi-san’s… enjoying it.)

Seizing the moment, I slam my hips, panpan, into her buttocks.

Pachiiin!! Paan♡ Paan♡ Paan♡ — Paan!!

“O… Ku♡ Nn… Au…♡”

“How is it, Miyabi-san!”

She hides her face, unreadable.

“I’m… not feeling anything.”

Her merciless words hit me as I thrust desperately.

※

<Miyabi’s Perspective>

A massive penis is inside my vagina.

Its owner is the man my lady, Ayaka, to whom I’m loyal, loves.

(I must judge if he’s worthy of her…)

Ayaka was hurt by that awful man. That’s why I’m hoping for this one.

…

I was born into the Amakawa family, a minor branch of the Saionji. Despite our low status, I was gifted from childhood, able to replicate anything I saw.

“You’ll serve the Saionji lady.”

I remember that day clearly. Though talented, I was a child under ten, and working in an unfamiliar mansion strained my mind.

Then—“Will you be my friend?”—Ayaka reached out to me.

Since then, we’ve been inseparable, sharing joys and hardships. When her marriage was arranged to a reputedly capable nobleman, I celebrated, believing her future secure.

But—

“What an ugly body… Stay away, you sow!”

“Kyaa!”

Our bright future turned to hell.

His perverse fetish despised adult women, targeting us too.

“Serve me? With that flabby body? Don’t mock me!”

A dry slap burned my cheek.

I trained with dildos for this day, to serve my new master. But that chance never came.

“Get me younger girls. Ones I like…”

Prepare children for abuse? Impossible. I could only endure.

Misfortune compounds.

“A tumor… in milady’s breast?”

“Yes, unfortunately.”

“Treatment?”

“Only mastectomy.”

Petan

I collapsed, my hips hitting the ground. The shock overwhelmed me, unable to accept reality.

“A—AAH!! AAAAAH!!”

For the first time, I screamed until my throat tore.

Ayaka’s childhood face—smiling, surprised, troubled, pouting—flashed and faded. Her stunning beauty at her wedding’s eve.

“Stay with me forever, Miyabi, okay?”

Her warm embrace… growing cold.

…

(It’s my fault for ignoring her stress.)

For three years, earnest Ayaka was mentally crushed. No time for self-blame.

I scoured modern surgery, regenerative medicine, Eastern pharmacology, even crackpot papers.

“Ugh… another dud. All scams for research funds.”

No easy answers. Time passed, my anxiety growing.

(I’m just a mediocre woman, good at using others’ work, deluded into thinking I’m exceptional.)

“If it’s come to this, maybe the occult…”

Lauded as a genius, relying on the occult? Laughable.

“God’s hand…? Breast massage…? Ridiculous.”

If that cured cancer, doctors wouldn’t exist. I tossed the report into the trash—

“Tsukihara…? Source: Tsukihara Yukino… Why her?”

A distant relative’s daughter, cherished by Ayaka for living nearby. Spreading false info?

No, she believes it.

“Let’s investigate.”

I ordered my subordinate to verify, emphasizing facts over bias.

“Unbelievable… Multiple witnesses confirm tumor cures?”

“Yes.”

“…Understood. You may go.”

The most absurd occult claim held a glimmer of truth. Clinging to hope, I headed to Ayaka’s room.

…

“Miyabi-san?”

“…It’s nothing.”

I must fulfill my duty as a maid.

“Let’s go harder.”

Gyu♡ Guni, Guniii♡

“Nn… Fuu… A…♡”

Her hips kneaded, pierced by a thick cock, electricity shoots up my spine, filling my head with pleasure.

(This… is God’s hand…)

Dochun♡ — Paan♡ Paan♡ Paan♡ Paan♡

“…Fuu… Fuu, nn… U”

“Haa… Haa… How’s this!!”

He pulls back, then slams his long cock in, pachiiin, crushing my buttocks, hitting deep.

Zudo♡♡♡

“—!!? (Ogo♡ Nnnu~~~♡♡♡)”

Burying my face in the pillow, I take a devastating hit, striking my deepest weak spot.

“Nfuuu… Oo… (Sex… is this intense♡)”

Paan♡ Paan♡ Paan♡ Paan♡

Relentless, his huge cock targets my portio, hitting erogenous zones I didn’t know, my vagina contracting on its own.

(He’s skilled… too skilled for a first-year high schooler. How many women has he had…? Auu♡)

“Miyabi-san! I’m feeling amazing! So you should too…!”

“Kuuu~~~n. I’m… not feeling anything…!”

(Lies. My body’s trembling, screaming with joy.)

But I can’t let him know. If he’s satisfied now, he won’t become worthy of milady.

“I’m… just… a maid…”

“Haa! Haa! Aaa, aaah!”

Dochu♡ Dochu♡ Dochu♡ Dochu♡ — Dochun!!

“Nn! U… Ku, aa…”

(No…! I’m coming♡ Coming♡ Auuu…♡)

“I’m cumming!!”

Dopyu♡ Byurubyururu♡

“Gu… (Ah♡ No… Coming, coming, coming~~~♡♡♡)”

Biku♡ Biku♡ Biku♡

An intense climax, unlike any dildo, makes my blood boil, my mind blank.

“Cumming… Your pussy’s so tight, it’s too good…”

His pulsing cock shoots semen at my cervix.

(Hot♡ Don’t press so hard♡)

He grinds his cock against my cervix during ejaculation, like a male instinct to impregnate.

(This… is sex♡♡♡)

“Nfuu… Fuu… Fuu… Uu”

“Miyabi-san, haa, haa… you okay?”

I can’t let this younger boy see my shameful face. Mustering my strength, I feign calm.

“Good work. You were very skilled.”

“Uh…? T-Thanks…?”

“Come back whenever you need relief.”

I stand on trembling legs, fixing my appearance.

“Satisfied?”

“Of course. It was amazing.”

“Thank you, master.”

I bow deeply, hiding my face, unable to suppress a smile.

“Huh?”

“I’ll handle what you can’t release with milady—my wife.”

“Huh? Huh?”

I’ve decided to entrust Ayaka—my lady, my wife—to this master.

I’ll mold him into the perfect man, for the Saionji family’s future. A training plan—studies, fitness, grooming, etiquette, and sex—is already forming.

“Fufu, how exciting…”

My heart races for the first time in ages.

※

I had sex with Ayaka, then Miyabi. Honestly, it was incredible… but Miyabi insists she didn’t climax.

(No way… my hands can sense a woman’s state.)

But she barely made a sound, so the truth’s unclear.

“I need to grow as a man…”

Lying on the guest bed, I ponder.

(Miyabi said she’d train me… Am I being made the master here?)

Despite a real husband, she called me “master,” like she won’t let me escape.

“Well, I’ve already done it…”

Exhausted from sex, my eyelids droop.