The physics of Japanese festivals obey a simple and cruel law: the volume of people is inversely proportional to the amount of oxygen available.
Kaito Tanaka sat on a blue plastic tarp, squeezed between Sakuta Azusagawa and a cooler. His knees brushed against Sakuta's. The collective body heat of the group was enough to incubate dragon eggs.
"Tanaka," Sakuta said, looking at the crowd passing like a river of yukatas and sweat. "Have you ever considered that maybe hell is just an eternal summer festival where the bathroom line never moves?"
"My theory is that hell is a time loop at a festival," Kaito replied, opening a can of lukewarm green tea. "With out-of-tune flute music on repeat."
"Deep," Sakuta agreed.
The two exchanged a look of mutual understanding. It was the "Dead Eyes Alliance." While the rest of the group radiated energy, they radiated the desire to be in an air-conditioned room.
In front of them, chaos unfolded.
Fia, in her role as "country cousin," had disappeared into the crowd five minutes ago and returned triumphant with six packs of yakisoba, three squid skewers, and a fox mask she wore on top of her head.
"Offerings!" she announced, dumping the food in the center of the circle. "The economic system of this festival is fascinating! I exchanged colored paper for carbohydrates!"
"That's called 'money', Fia-chan," Kunimi said, laughing and grabbing a skewer. "Your cousin is funny, Tanaka."
"She suffered a head injury as a child," Kaito lied, without blinking. "Many times. With magazines."
While the food was distributed, Kaito focused his attention on the real battlefield: the quantum love triangle (or square).
Yuuma Kunimi sat in the center, radiating that "Human Golden Retriever" aura that seemed to attract all carbon-based life forms. To his left was the Original Futaba (Rio), eating yakisoba shyly, her glasses reflecting the lantern lights. To his right was the Other Futaba (Reo), disguised as a cousin, maintaining an elegant posture but with eyes fixed on Kunimi's every move.
"So, Reo-san," Kunimi said, turning to her with a polite smile. "Do you study at the same university as Kaito-san's cousin?"
Reo froze. The "college student" lie required improvisation.
"Ah... yes!" she replied, tossing her hair back. "I study... Science. Social... Applied... Sciences."
"Sounds tough," Kunimi said, impressed. "Rio is a genius too. Must be a family thing."
He turned to the Original Rio. "Hey, Futaba. Do you want water? I bought an extra. I know you get headaches if you dehydrate in the heat."
He extended a bottle of cold mineral water to Rio.
Kaito saw the exact moment the penny dropped for the Other Futaba.
Kunimi was being polite and charming with "Reo," the pretty, mature girl. But he was being thoughtful with Rio, the girl with glasses and the discreet yukata. He knew she got headaches. He knew what she needed before she asked.
Reo looked at the water bottle in her "cousin's" hands. Her eyes wavered. All the makeup, the confident posture, the Instagram cleavage... none of that bought that casual intimacy. None of that bought the fact that Kunimi knew how she felt.
"Thank you, Kunimi," Rio whispered, taking the water, face flushed.
Reo lowered her gaze to her own yakisoba. She didn't look jealous of the other. She looked... sad. And resigned.
"Bingo," Kaito thought, chewing a piece of cabbage. "The 'Superficial Validation' variable has just collided with the 'Real Connection' constant. The system is ready for reintegration."
"What are you analyzing with that face of someone solving a quadratic equation?" Mai asked, sitting next to him and stealing a piece of his squid.
"I am observing physics applied to emotions," Kaito muttered. "And you stole my squid."
"Administration fee," she replied, smiling. "You're doing well, Kaito. No one suspected. Except maybe Sakuta, but he's too smart for his own good."
Indeed, Sakuta was watching the two Futabas with a calculating look, but whenever Kaito looked at him, Sakuta raised his cup in a silent toast and went back to talking to Fia about the existence of aliens.
BOOM.
The first firework exploded in the night sky, a flower of golden light that made the crowd sigh in unison.
Conversation died. Everyone looked up.
Kaito leaned back on his elbows. He looked at the colorful explosions. Red. Green. Blue. They were pretty, he had to admit. But they were also loud and fleeting.
He looked to the side.
Rio and Reo were looking at the sky. Their profiles were identical under the strobe light of the fireworks. And, in a moment of perfect synchrony, both sighed at the same time when a heart-shaped firework exploded.
They looked at each other.
There was no hate in Reo's gaze. There was no fear in Rio's gaze. There was only recognition.
"I am you," said one's look.
"And I am you," answered the other's.
"It is time," Kaito thought.
The grand finale lit up Enoshima Bay, turning night into day for ten glorious and deafening seconds. When the last ember faded and the smoke began to dissipate, the crowd's applause filled the vacuum.
"It's over," Kaito said, standing up immediately and brushing dust off his yukata. "The visual spectacle has concluded. Crowd dispersion will be chaotic. I suggest strategic retreat."
"Always so romantic, Tanaka," Kunimi laughed, standing up and stretching. "Well, I have practice early tomorrow. Gotta go."
"Me too," Sakuta said.
Sakuta stopped in front of Kaito. He looked at the two Futabas, then at Kaito.
"Good job with the... 'family', Tanaka," Sakuta said, with a smirk. "Genetics is a complicated thing, isn't it?"
"Extremely," Kaito agreed.
"Take care of them. And the loud little cousin."
"She is not my responsibility," Kaito tried to deny, but Sakuta was already walking away, waving without looking back.
Kunimi said goodbye to everyone. "Bye, Rio! Bye, Reo-san! It was a pleasure! Let's play basketball sometime!"
He disappeared into the crowd.
The remaining group stood on the bank of the river of people.
Kaito, Mai, Fia, Rio, and Reo.
"What now?" Reo asked, her voice sounding tired, the "confident cousin" persona melting like wax. "To your apartment, Tanaka? I don't think we fit in the 'Divine Sandwich' again."
Kaito looked at her. Then he looked in the direction of the wealthy residential area.
"No," Kaito said. "My hostel contract has expired. And my back demands reparations."
He pointed north.
"We are going to Futaba's house."
The two Futabas blinked.
"To... my house?" Rio asked. "But... Reo has the key and..."
"Both of you have the key," Kaito cut in. "And the house has five bedrooms, three bathrooms, and a sofa that costs more than my life. It is logistically offensive not to use that infrastructure."
"Besides," Mai intervened, understanding the plan, "we need space for the final conversation. And Kaito's apartment has thin walls. The neighbors don't need to hear about quantum physics and puberty crises."
"AND IT HAS CENTRAL AIR CONDITIONING!" Fia shouted, already starting to float toward the mansion. "LET'S GO! THE MANSION OF SCIENCE AWAITS US!"
Rio looked at Reo. Reo looked at Rio.
"Do you mind?" Reo asked timidly. "If I... come back?"
Rio adjusted her glasses. "It is your house too. Technically."
Kaito started walking, leading the way away from the confusion, toward silence and the comfort of air conditioning.
"Let's move," he grumbled, pulling at the yukata collar. "If I have to wear these clothes for one more hour, I'm suing Japan for moral damages."
The group followed him. The night wasn't over yet, and the hardest part—reintegration—was about to begin. But at least, Kaito thought, it would happen on an Italian leather sofa.