Parameter Supremacy: The Man Who Seizes a Harem Through Sheer Effort. - Chapter 73.

Episode 73: Playing at the Beach.

Inside the forbidden women’s changing room.

It was cramped, but mirrors and simple benches lined the space, and the lively chatter of girls echoed from every direction. Matsuri had already taken off her T-shirt and was adjusting the straps of her vibrant red bikini.

“Look, Moe-cchi~! What do you think!? Does it make me look hot!?”

“M-Matsuri-chan… Isn’t that a bit too bold…? It’s showing quite a lot…”

Moe stood there with her face bright red, still wrapped tightly in her towel.

“You need to change quickly too~ Come on, we picked out something cute and a little naughty for you, remember?”

“Eh? Y-Yeah, I know, but… I’m still feeling a bit shy.”

Shiina watched the two of them with a gentle smile.

“You don’t need to worry, Moe. I think it’s cute, and I’m sure it’ll look great on you.”

“…But Shii-chan is definitely cuter…”

“Me? I’m just normal. My swimsuit is pretty simple too.”

Even as she said that, Shiina was wearing a mature white bikini with thin navy lines. Her hair was tied up, and the shadows falling from her shoulders to her chest created a striking silhouette. Despite her words, her figure was undeniably eye-catching.

Matsuri made a frustrated “Gunuu” face and pointed at Shiina.

“That’s not normal!! Shii-chan has an amazing body, so everything looks perfect on you!!”

“Stop it already…”

Shiina turned red all the way to her ears and hid her chest with the towel. Beside her, Moe finally gathered her courage, removed her towel, and checked her reflection in the pale blue bikini adorned with a ribbon at the chest.

“…Does it look weird…?”

“It’s cute! It really suits you!”

“Come on, look in the mirror, Moe. Go on, give us a spin?”

“I-I’m not spinning!”

Joyful laughter filled the changing room.

***

The curtain of the women’s changing room fluttered, and the three girls emerged one after another.

The first to appear was Matsuri-chan. Her vivid red bikini was quite daring in design. It looked like even a slight jolt might cause her chest to spill out. A large beach towel was draped over her slender shoulders.

“Sorry to keep you waiting~! Ta-da!”

“Isn’t that a bit too flashy, Matsuri-chan?”

“Hey! You can praise me more, you know? So, how is it?”

Matsuri-chan struck a pose with her hands on her hips.

“Ugh… Honestly, it looks good on you. It’s just a little too sexy.”

“Summer calls for this much at least!”

Next, Moe peeked out shyly.

“…Please don’t stare too much, okay…?”

The light blue swimsuit suited Moe’s modest and graceful nature perfectly, while still looking undeniably cute. The ribbon at her chest was a lovely accent. And yes—she was very well-endowed. The way she bashfully fiddled with her hair using her fingertips was strangely endearing.

“Moe, that swimsuit looks really good on you. It’s cute.”

“…Th-Thank you…”

Finally, Shiina stepped out slowly.

A simple white and navy bikini. It wasn’t flashy, yet it drew the eye instantly. I already knew she had an overwhelming figure, but seeing it like this was still breathtaking. Her tied-up hair swayed in the sea breeze, creating a beautiful contrast with her fair skin.

“…How does it look?”

“…It suits you perfectly. Yeah. It looks amazing.”

The moment I said it, Shiina glanced away slightly and smiled.

“I see. I’m glad.”

Her ears were bright red. It was so adorable that my words caught in my throat for a second.

“Alright, alright! You two can flirt later! Let’s go to the sea!”

Matsuri-chan made a fuss, Moe laughed, and Shiina secretly gave my hand a light pinch.

***

“Hey Ryuuji, can I ask you for a favor?”

“Hm? What is it?”

Shiina shook a bottle of sunscreen in front of me.

“Can you put it on my back? I can’t reach the middle part.”

“O-Okay. Sure…”

“Yeah. Sorry about this, okay? But I really can’t reach it myself.”

With those words, Shiina turned over and lay face-down on the towel. She swept her hair forward, revealing the smooth line of her back. The strings of her simple white and navy bikini were tied neatly, and just below them stretched her pale, silky skin.

“…Alright, here I go.”

I squeezed an appropriate amount of sunscreen onto my palm, rubbed it between both hands, and gently touched her back.

Shiina flinched at the cool sensation.

“Hyah… It’s cold…”

“Sorry. I touched you too suddenly.”

“It’s fine… Keep going.”

I touched her back again and slowly spread the sunscreen with my fingertips. The cream melted into her warm skin. Every time I moved, her shoulder blades shifted subtly.

“Mmm… That actually feels kind of nice.”

Shiina closed her eyes and let out a small sigh as she felt the sea breeze. Feeling awkward looking at her profile, I turned my face slightly away and continued the task in silence.

“…There, the middle is done.”

“Thanks. Then next… the front too…”

“The front!?”

“Just kidding, fufu. What were you expecting~?”

“Sh-Shut up… Don’t tease me.”

I let out a relieved breath. Shiina sat up, turned around, and gave me a bright smile.

“Thank you, Ryuuji. You saved me.”

“No problem… We’re dating, so this much is normal.”

For a brief moment, Shiina’s eyes widened at my words, then she spoke in a soft, sweet voice.

“That’s right. We’re lovers, after all♡”

At that instant, the wind blew, and Shiina’s damp hair brushed gently against my arm. It was such a small thing, yet my heart beat a little faster.

“…Alright, time for me to head into the sea!”

With that, Shiina stood up and ran off. I watched her retreating figure and let out a long breath.

“…Seriously. Of course I’d get nervous with something like this.”

***

“Ryuuji! Hurry up and come over here~!”

Shiina, who had run into the sea, jumped into the incoming waves and waved at me with water up to her chest.

“You’re too fast…!”

As I headed toward the sea with a wry smile, Matsuri-chan came running up from behind, kicking up white sand with light steps.

“Shii-chan really is a sports girl, huh!”

“You’re running pretty fast yourself, Matsuri-chan.”

“Because it’s the sea!? Of course I want to jump in!!”

Her smiling face as she said that was so bright I found myself momentarily captivated. With her hair tied up, her slender neck was clearly visible, and combined with her swimsuit, she looked more alluring than her usual energetic self.

When the two of us entered the water, Moe was already standing near the shore, hugging a float ring.

“R-Ryuuji-kun… Um, it’s deeper than I thought…”

“It’s only up to your knees right there.”

“B-But when the waves come, I float away!”

Moe clutched the round blue float ring to her chest, her body gently lifting with each wave.

Matsuri waded through the water and rushed over with a big splash.

“Moe-cchi~! Lend me the float ring~!”

“N-No! I’ll drown without it!”

“No way!”

“It’s true!”

Watching their exchange, both Shiina and I burst out laughing.

“Don’t push yourself, Moe. It’s better not to go too far out.”

“O-Okay… This is plenty for me…”

Still hugging the float ring, Moe cautiously stepped further into the sea. She flinched at the cold water touching her legs but smiled with clear enjoyment.

***

“Here it comes~!”

At Matsuri-chan’s shout, a large wave rolled in.

“Wah!?”

“Kyaa!”

Moe on her float ring bobbed upward, Shiina lightly jumped to let the wave pass, and Matsuri-chan and I, submerged up to our chests, took the full force of it.

“Ugh! It’s salty!”

“This is fun! Bring on the next one!”

Matsuri-chan raised her arms, fully hyped up. I had felt it during the summer festival too—she always gave her all when it came to having fun.

A slightly bigger wave rose up and crashed directly into Matsuri-chan’s chest.

“Kyaa!”

A short scream escaped her. For a moment, her shoulder strap stretched dangerously.

—Ah, crap.

As the water receded, I clearly saw that the right shoulder strap of her bikini had almost completely slipped off.

Matsuri-chan herself hadn’t noticed yet. She was too busy trying to regain her balance after the wave, flailing her arms.

In an instant, I closed the distance.

“Matsuri-chan, don’t move!!”

“Eh, what—Kyaaa!? W-Wait!? Sagara-cchi, you’re too close!”

“Just stay still! Seriously, don’t move!”

I held her shoulder with one hand and quickly grabbed the slipping strap with the other. Another wave crashed over us, splashing seawater straight into my face.

Damn, it’s salty.

“…If this had come off completely, it would’ve been a total disaster. Pay attention.”

When I whispered that, Matsuri-chan’s face turned bright red in an instant.

“W-Wait… It wasn’t on purpose…! This is so embarrassing…!”

Her voice was trembling. This wasn’t the usual bold Matsuri-chan.

“There, it’s fixed. You can move now.”

When I gently released her, Matsuri-chan pressed a hand to her chest and looked down shyly.

“…Thanks. Sagara-cchi, you’ve always been so reliable…”

“We haven’t even known each other that long.”

“Ahaha. That’s true. …But thank you, really.”

Matsuri-chan finally smiled, though her cheeks were still flushed red. In the distance, Moe waved cheerfully from her float ring, completely oblivious.

“Are you two okay~? It looked like you were making a big commotion.”

Shiina didn’t seem to have noticed and was laughing while catching waves with both hands.

“Ryuuji, want to swim a little?”

“Eh? Sure, I don’t mind…”

“Then let’s go out a bit further!”

Shiina gently tugged on my arm. Her innocent excitement made my chest stir. Still, moving away from this spot brought one concern.

I turned back to look at Moe.

“Moe, will you be okay by yourself?”

“Y-Yeah… I’m fine. I’ll watch from here. Go swim with Shii-chan.”

“Matsuri-chan, I’m counting on you! Don’t take your eyes off Moe.”

“Leave it to me, Sagara-cchi! I’ll protect Moe-cchi!”

“S-Stop that! I have the float ring, so I won’t drown!”

Feeling reassured by their usual bickering, I turned toward Shiina.

The sun sparkled on the water’s surface. When I reached out, the light danced between my fingers.

Shiina swam forward with a light breaststroke and glanced back.

“Ryuuji, are you keeping up?”

“You’re too fast, Shiina…!”

“Sorry, sorry. But it feels so good.”

Shiina flipped onto her back and floated gently. She looked up at the blue sky and spread her arms wide in the sea.

“Haa… I’m so happy…”

Those quiet words lingered in my ears. The waves, the wind, the light—everything carried the scent of summer, and right in the middle of it all was Shiina.

“Ryuuji.”

“Hm?”

“This summer has been really fun.”

Her smile was so genuine that it was hard to look at directly.

“…Yeah. It’s because I got to spend it with you.”

Honestly, that was all I could say.

“M-Moe-cchi! Over here! Wave’s coming!”

“W-Wait, Matsuri-chan! Don’t move so much, it’s scary…!”

The lively voices of the two girls echoed from afar. Shiina heard them and let out a small laugh.

“They sound like they’re having fun.”

“They really do. I guess this is what childhood friends are like.”

“Yeah. But it’s not just because they’re childhood friends.”

The light of the sea shimmered and reflected in Shiina’s eyes. I floated beside her, letting the waves carry me.

***

The sun began to tilt, and the shadows of the parasols stretched long across the sand. The lively noise of the beach that had filled our ears earlier gradually faded as evening approached.

“—Should we start heading back soon?”

Shiina turned to us while pressing a towel to her damp hair. Her hair was still heavy with seawater in places, but her expression looked deeply satisfied.

“Yeees… That was so much fun.”

Moe hugged her slightly deflated float ring and gazed longingly toward the sea. She had probably spent the most time floating in the water today.

In contrast, Matsuri-chan was tugging at her swimsuit, which was clinging to her bottom, and muttered in a lower tone than usual, “…I’m… tired…”

Well, after making that much noise, it was only natural.

We left the sandy beach and stepped onto the paved promenade. The sea breeze felt a little gentler now. The evening sky, blending blue and orange, slowly melted over the ocean.

“Haa… I think I really got sunburned…”

Shiina looked at her arms and smiled wryly.

“A little tan actually looks cute on you.”

“…Muu. Do you like tanned gals, Ryuuji?”

“No, no. I just meant a light tan looks healthy.”

As we talked, Matsuri-chan suddenly elbowed me from the side.

“Sagara-cchi, there’s a high-quality pale gal right here. What do you think?”

“You stay quiet.”

Matsuri-chan grinned mischievously as she walked beside me. In response, I gave her a light flick on the forehead.

“Oww~!”

I apologized to the teary-eyed Matsuri-chan as we headed toward the shower rooms at the beach house.

After rinsing off the salt with a quick shower and changing back into our clothes, we walked toward the shopping street with still-damp hair. Our four shadows stretched across the asphalt, swaying gently. Originally, one of those shadows might have belonged to Satou Minato instead of me—that thought crossed my mind.

“I’m getting hungry…”

Moe pressed a hand to her stomach and murmured.

“You were just floating around the whole time~”

“Even so, I still get hungry!”

Moe’s complaint toward Matsuri-chan was oddly cute, and both Shiina and I couldn’t help but laugh.

We bought shaved ice from a small stall and ate it while walking. The evening breeze felt pleasant against our flushed cheeks.

“Ryuuji, here.”

Shiina scooped some of her shaved ice with a spoon and held it out to me. It was strawberry flavor. After meeting Shiina, I had learned that the correct response in moments like this was to accept it honestly.

“…Mm. It’s sweet.”

“Right?”

She smiled softly. A little behind us, Matsuri-chan had her arms crossed and was muttering complaints.

“What’s with that… lovey-dovey atmosphere…”

“It’s fine, isn’t it, Matsuri-chan? Today was really fun.”

Moe tried to soothe her, but Matsuri-chan kept her cheeks puffed out.

We passed through the shopping street, and the nearest station came into view. We leaned against the railing and waited for the train.

“I don’t want to go home yet…”

Moe gazed toward the sea from the edge of the platform and whispered softly.

I smiled wryly and replied.

“We can come again.”

Shiina quietly reached out beside me and gently touched my fingers.

“…Yeah. Let’s come again, all of us.”

Shiina’s profile, bathed in the light of the setting sun, looked incredibly beautiful.

The announcement played, and the train’s lights approached.

The sea breeze swept across the platform. It was slightly chilly, but the heat and laughter of the day still lingered warmly inside us.

We boarded the train together.