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The front door clicked shut, signaling the end of a long, relaxing afternoon. Usada Pekora kicked off her shoes, stretching her arms high above her head. She had just returned from the public bath with Flare, Marine, and Noel—an adventure that was equal parts therapeutic and chaotic. Now, all she wanted was to curl up in bed and maybe play some games.
"Oha, Pekora-peko. You took your time," a familiar cool voice called out from the bedroom.
Pekora walked in, still toweling off her damp hair. "Ah, Suisei? It was crowded, you know peko. Marine was being loud in the washing area, as usual..."
She trailed off, her eyes landing on her girlfriend. Suisei was standing in front of the full-length mirror, striking a pose with her hands on her hips. She had a mischievous glint in her blue eyes.
"I’ve finished changing," Suisei announced, turning to face Pekora. "Well? What do you think?"
Pekora blinked, expecting a new dress, perhaps a sleek stage outfit for an upcoming concert, or maybe just some cute pajamas. Instead, her jaw dropped.
Suisei was wearing a pair of vibrant, printed swimming board shorts. And absolutely nothing else.
Her pale, flat chest was completely bare, smooth skin blending into the collarbones. Pekora’s face instantly flushed a deep red.
"E-eh?!" Pekora sputtered, taking a step back. "S-Suisei? Are—are you serious right now? You said you finished changing, but that’s not an outfit! That’s just—peko!"
Suisei tilted her head,her suicopath smile etched on her face. “It would had been a huge problem if you didn’t have a reaction on your face, but I’m glad my chest is still to your liking.”
"You're joking!" Pekora yelped, covering her eyes with one hand but peeking through her fingers. "Why are you naked from the waist up?!"
"Actually, this is for a thought experiment," Suisei said, walking over to the rabbit, completely unbothered by her lack of top. "I was in a stream collab the other day, and I heard Matsuri and having a discussion. They were arguing about whether, since they are flat, they could theoretically get away with wearing just board shorts and no top at the beach."
Pekora stared at her. "You... you listened to Matsuri and Laplus? And took it seriously?"
"Of course," Suisei nodded, crossing her arms. "It was tinged with their usual perverted reasoning, sure, but I was genuinely curious. So, I bought a pair of board shorts to test the theory."
She spun around once, the shorts fluttering. "So, tell me. Honestly. Do you think I could get away with going to the beach like this?"
Pekora looked at her like she had just escaped from a high-security asylum. She sighed, stepping closer and pointing an accusing finger at Suisei’s chest.
"You're asking if you can get away with it?" Pekora deadpanned. "Suisei, look at you. Your nipples are rock hard."
Suisei gasped, "Hi-!"
She yelped in surprise, looking down. Sure enough, the exposure to the cool air had caused a very obvious reaction. Her cheeks instantly flared up with heat, matching Pekora’s shade. She quickly crossed her arms over her chest, hiding the evidence better than she would had admitted. “W-wait! It's cold in here! That's just—that's a biological response!"
Pekora couldn't help but face palm at the normally composed idol's panic. "You're an idiot peko. You really thought this through, huh?"
After a few seconds of Suisei trying to burn a hole through the floor with her embarrassment, Pekora sighed. "So, what’s the hold up? Why haven't you put on a shirt, a dress, or even just a bra?"
Suisei bit her lip, hesitating. Slowly, she forced herself to remove her arms from her chest, her pride warring with her modesty. "I... I hadn't yet got a good look in the mirror. I need to estimate if I would pass."
She turned back to the full-length mirror, scrutinizing her reflection. She stood sideways, tilting her head. "Hmm... you know, if I ignore the temperature, the line is actually quite smooth. My chest does blend in with the rest of my torso. I really could almost get away with it..."
She seemed mesmerized by her own flatness, striking poses that accentuated her slender frame. Pekora watched her, her annoyance turning into a mixture of amusement and affection. The blue-haired idol was hopeless sometimes.
Pekora walked up behind her, grabbing the hem of her own t-shirt. In one swift motion, she stripped off her shirt, leaving her in just a skirt and her bra, and thrust the shirt toward Suisei.
"Here. Put this on before you freeze, you weirdo," Pekora said.
Suisei turned around, catching the shirt. She looked at Pekora, who was standing there topless from the waist up, and a wicked grin returned to her face. "My, my... Pekora. Are you getting shy? Surely you know that you can’t get away being topless at the beach.”
Pekora scoffed, crossing her arms. "Don't get ahead of yourself, peko. I just don't want my girlfriend getting a cold because she's walking around with her non-existent flat chest out in the air! It's for your health!"
"Is that so?" Suisei laughed. In a flash, she threw the shirt, grabbed Pekora by the waist, and tackled her backward onto the bed.
"Wah—Peko!" Pekora shouted as she landed on the mattress.
Suisei climbed on top of her, straddling her hips, pinning her down. "You're so cute when you worry about me."
"S-Suisei! Get off!" Pekora struggled, but there was no real malice in it.
"I think you need a reward," Suisei teased, leaning down, her eyes gleaming with that distinct 'snu-snu' energy. "Or maybe a punishment for calling me flat just now?"
She wiggled her eyebrows and leaned in to put her chest on top of Pekora’s face blinding her.
"G-Get off! You're heavy peko!" Pekora squealed. She decided to play along, going limp and letting her tongue loll out slightly. "Ugh... I'm suffocating... the pressure... the ego..."
Suisei gasped, lifting her head. "Oh, I see! Playing the victim? I'll show you pressu—"
Pekora suddenly shot her hands up, tickling Suisei’s sides aggressively.
"Hyaaa!" Suisei shrieked, her composure shattering instantly. The tickling sensation was too much. She collapsed onto her side next to Pekora, giggling uncontrollably, clutching her stomach. "S-stop! No fair! Pekora, you cheater!"
Pekora sat up, panting slightly, looking down at her defeated girlfriend. Suisei was laughing, her hair fanned out across the pillow, face flushed from the tickle attack. Pekora felt her annoyance melt away; she really did love this weirdo.
Pekora smirked, glancing down at her own chest, which was significantly larger than Suisei's. Two can play at this game.
"You know," Pekora murmured, reaching behind her back to unclasp her bra. "If we're comparing sizes..."
She let the bra fall away and then straddled Suisei, reversing their positions. Before the comet could react, Pekora leaned forward, pushing her own breasts directly into Suisei’s face.
"How about this, peko?" Pekora teased.
Suisei’s eyes went wide. The softness engulfed her vision, and she let out a muffled "Mmph?!" It was incredibly hot, having her girlfriend this close, confident, and dominating the space. But as the initial surprise faded, a familiar pang of competitive inadequacy hit her.
She remembered the board shorts. She remembered the Matsuri and Laplus conversation. Being reminded of the small but significant size difference made her pout instantly.
Suisei grunted, summoning her idol strength. She grabbed Pekora by the waist and wrestled back, rolling them over with a sudden surge of energy. She pinned Pekora down again and frantically reached out to the side, grabbing the discarded shirt Pekora had handed her earlier.
She shoved the shirt over Pekora’s chest, effectively covering the "threat."
"Hey!" Pekora laughed, struggling against Suisei’s grip.
Suisei sat back on her heels, breathing hard, staring down at Pekora with a deep, adorable pout on her face. Her arms were crossed tightly over her own chest again, guarding her modesty.
"It's not fair," Suisei grumbled, looking away. "Using your chest in a fight that I can’t compete with.”
Pekora looked up at her girlfriend, seeing the blush on Suisei's cheeks and the pout on her lips. She knew she had won this round. Suisei’s flat chest was one of her weak spots—she acted confident about it, but moments like this proved she was still sensitive.
Pekora burst out laughing, reaching up to poke Suisei’s puffed-out cheek. "You're so cute when you're jealous, Suichan!"
"I am not jealous!" Suisei insisted, though her pout only deepened.
"Sure, sure peko," Pekora giggled, pulling Suisei down into a hug. "Let me warm you up before you catch a cold for real."