How Using My Oppai Skill to Enlarge My Sister’s Breasts Led to Building a Harem - Chapter 51.4

Chapter 51.4

Days after the pro wrestling show, I walk the city alone to meet someone.

The Saionji staff scolded me to “act like a Saionji,” but I can’t bring an entourage to a date.

It’s still early, the streets bustling, the target shopping mall packed. Arriving ahead of schedule, I find my date already waiting.

“Hey, been a while.”

My date, Shishidou Kokoro-san, stands before me in a skimpy outfit, barely covering her stunning figure.

“Hello, Shishidou-san.”

At her name, she glances around, flustered, then relaxes with a sigh.

“Don’t call me that. I’m kinda famous, you know.”

“Ah, sorry…”

Caught staring at her beauty, I forgot—she was a mega-popular pro wrestler until recently. Slipping on sunglasses for caution, she grabs my arm, starting to walk.

“Whatever, let’s go?”

“Sure.”

We fought in the ring and fucked once, but that was work. Yet, she contacted me through the adult company.

Her message was passionate—

“I can’t forget you.”

“Just one more time… I want to see you.”

So, I told her about my promised partners but agreed to meet.

Now, Shishidou Kokoro-san clings to my arm, strolling happily.

(She’s gorgeous…)

Her fierce ring persona was an act. In person, she’s just a stunning older sister.

“Something wrong?”

“Nah… Just thinking you’re beautiful.”

“Huh? Geez, don’t tease me.”

Unused to compliments, she blushes, flustered.

“You’re the one…”

“?”

Her face red, she sneaks side-glances, then speaks.

“You’re really cool…”

Her clumsy praise feels so like her, my face lights up with a smile.

“Thanks, uh… Kokoro-san.”

“U-Uh… Fufu♪”

We wander the mall, browsing clothes, trinkets, quirky gadgets, and cute animals at a pet shop.

A normal date. But her love for movement shines—

“Here!”

“Whoa!”

She gets hooked on ping-pong at an arcade.

“Your knees… Are they okay!?”

“Hah! Fine for this—Sei!”

Spotting my floated return, Kokoro-san smashes a forehand, the topspin too fierce for me to counter, sailing off the table.

“Yay!”

“Wow, you’re good, Kokoro-san.”

Her victory pose earns my honest admiration.

“I’m pretty good at sports.”

“Jealous… I suck at ball games.”

“Hmm. But you’ve got fighting talent, don’t you?”

“Maybe…”

My physicality’s solid, and combat relies on footwork and timing. But ball games? I can chase but can’t return.

“Phew♪ Nice sweat. Wanna rest?”

“Sounds good. There’s a cozy café over there.”

“Let’s do it.”

Kokoro-san returns the paddle and ball, offering to pay for both. When I suggest splitting—

“No way I’m letting a student pay. Leave it to your big sis.”

“Uh… Thanks.”

She taps her phone to settle the bill.

(Getting treated by a woman feels… new.)

Since joining the Saionji, money’s no issue, so covering dates is nothing. But Kokoro-san acts like it’s her duty, so I let her, respecting her pride.

“Don’t worry about money. I made a ton, you know.”

“Impressive. That’s cool.”

As a top wrestler, she earned her wealth through her own grit, unlike me, who lucked into Saionji riches. I respect that.

Pleased, she hooks my arm again, strolling through the mall. I steal glances at her cute, beaming smile.

(So beautiful… And her sweat smells amazing…)

Why does a beauty’s sweat smell so sweet? Pondering, we head to the café, picking a secluded seat.

“Nice, calm place.”

Kokoro-san hands me the menu.

(So considerate… And her sweat-soaked top’s see-through…)

It’s erotic. Her cleavage glistens with sweat, and I can’t help staring. She catches me, laughing.

“Geez, you perv.”

“Haha, sorry. You’re just too gorgeous.”

I apologize, tossing out another compliment.

“Saying that again… I’m an old lady compared to you, right?”

She doesn’t buy my words, brushing them off. I deny it fiercely.

“No way! You’re an amazing woman, so captivating.”

“Really? I’m over a decade older.”

“Doesn’t matter. Spending time with you, I see how incredible you are.”

I’m genuinely falling for her. Unlike our physical fling, I want a real relationship with the woman before me.

“R-Really? A young guy saying that… It’s embarrassing…”

She seems flattered, so I pour out my feelings. At 29, she’s much older than my 17, but age doesn’t faze me in love. A captivating woman’s value is timeless.

Then, she stares at me, speaking softly.

“You’re the one who’s a catch…”

“Huh? You think?”

“Yeah, all clean-cut and sporty—”

I keep myself neat, hygiene a priority.

“—At least, you’re my type…”

My looks hit her sweet spot, and she’s clearly into me. Getting praised by a beauty like her sends me soaring.

“I wanna know more about you.”

“M-Me? My life’s not that special.”

“Please.”

I’ve researched her career, but I crave her personal journey, her feelings.

“Well… Around your age, I was obsessed with wrestling…”

Shidou Kokoro—that’s her real name. National competitions, Olympic hopeful—but injuries piled up.

“I never made the Olympics… So I went pro.”

Changing her name to Shishidou Kokoro, she turned pro, fighting globally in MMA. But women’s MMA paid peanuts—tens of thousands per match, unlivable.

“So, pro wrestling?”

“Yup. It’s tough, but you can wrestle daily.”

Like baseball, it’s less intense than soccer, allowing daily matches, making it a better spectacle.

“Still, my body hit its limit.”

Her joints, especially, couldn’t take years of abuse.

“You know the rest. Not a big deal, right?”

“No way.”

I admire her for succeeding as an athlete through sheer will. She’s truly remarkable.

“Tell me about you. What’s your life like?”

“Me? Nothing special—”

School, studying, training, student council, and… stuff I can’t advertise.

My life, within what I can share, is embarrassingly mundane.

“Teio University hopeful? You’re that smart…”

“It’s not guaranteed yet.”

“But you’re acing mocks, right?”

Thanks to Miyabi-san’s one-on-one tutoring. Not my effort alone.

“Student council too… Opposite of my life.”

She wasn’t big on academics.

“No brains, so I earned with my body.”

“Still, you’re amazing.”

Smarts don’t make you great. Studying doesn’t guarantee you make others happy.

She’s brought smiles through her efforts. I admire her way of life.

“Young guy looking at me like that… It’s embarrassing.”

I don’t know my own expression, but her reaction suggests it’s not bad.

“Alright, big sis is taking charge today!”

“???”

“Dinner’s on me—yakiniku.”

Wrestlers love meat. She insists on paying, driving me to her favorite barbecue joint.

“Eat up! Meat builds a strong body.”

“Thanks! Itadakimasu!”

“Young guys are the best…”

She grills, piling my plate with meat.

“Tongue and kalbi are tasty, but fatty.”

Her go-to spot serves tenderloin and thigh, softened with special sauce. But she prioritizes my plate, barely eating.

“Eat too, Kokoro-san. I’ll grill.”

Concerned, I reach for her tongs—

“It’s fine. I don’t need much anymore…”

Her lonely smile lingers.

(She’s still attached…)

“Here, eat more. Get strong.”

Her expression, like she’s done and passing the torch to me, sticks in my mind.

※

“Alright, I’ll drive you home.”

“Thanks for the ride. And the meal.”

“Fufu, you ate so much, I loved it. Youth’s great…”

After treating me, Kokoro-san offers to drive me home. I slide into her car’s passenger seat.

Her car glides through the night city, smoothly passing the urban bustle, following my directions.

(It’s a quick trip…)

The Saionji estate’s ten minutes away. Feeling reluctant, I make a suggestion.

“Wanna stop at that hill? The night view’s amazing.”

“Oh? Fufu, let’s take a break then.”

Eager, she drives up a quiet slope, finding a perfect spot to park.

“The stars are gorgeous…”

Dimly lit, with rare traffic, it’s a local secret. I buy drinks from a lone vending machine, and as we sip, a cool breeze brushes our skin.

The refreshing wind sweeps away the summer heat and the subtle distance between us.

“Kokoro-san—”

The somber mood shifts, and I ask what’s been on my mind.

“What’re you gonna do now?”

She’s pushed her body to the brink. I delivered the final blow, so I feel responsible.

“Do… Well, who knows…”

Placing her can on the fence, her gaze drifts to the sky—not searching, but reflecting her tangled thoughts, her eyes wavering.

“All I had was fighting… But I need something new, right?”

“…”

If she’s found a new dream, I’ll back her fully, using every connection to help her start fresh. But if not, what can I do?

“I’m hopeless… Always winging it, no plan…”

“That’s not true.”

Taking action is incredible. Overcoming obstacles to reach the top in one field—that’s worth pride. I share my admiration.

“Right… Thanks. But that’s the past. I was young, reckless… Can’t go back.”

Closing her eyes, she recalls old days. Unable to leave her like that, I hug her from behind.

“I want you to do what you truly want. Not what’s possible, but what you desire.”

“That’s…”

“I’ll help with anything. Even fix your knees.”

“No way that’s—”

I don’t know if my power can heal her. If not, I’ll find the best doctor in Saionji’s reach.

Because I think Kokoro-san, throwing herself into something fully, is cooler than giving up.

“I love you fighting.”

“…”

“For me, will you try one more time?”

Wanting her to shine in her element might be selfish. Still—

“I’ll always support you. When it’s tough, I’ll hold you up.”

“…”

My arms tighten around her. Strong enough to hurt a normal woman, I keep holding.

“Then… you’ll take responsibility?”

“I will. No matter what, I’ll love you forever.”

“Right…”

Her hand rests on my arm, patting to ease up. When I loosen, she turns halfway in my arms, pressing her lips to mine.

Unlike before, a gentle kiss, lips only. They tremble slightly, nervous.

(Her anxiety… and joy, I feel them…)

I keep holding her softly. Her trembling slowly fades.

“N, haa… Then—maybe I’ll try one more time.”

“—Yes.”

A third kiss, sweeter than the last, our hearts aligned.

Savoring her lips, my instincts crave her, my lower body raging.

“Kokoro-san, the car…”

“Yup…♡”

No words needed—we climb in, instantly seeking each other.