Aiba first really noticed when he was about fifteen. He and Nino had been good friends going on two years, and they were about as close as a pair of people could be (when you were all of fifteen).
It was midsummer, hot and muggy. Most, if they had the luxury, were left to squat in front of old oscillating fans in their underwear, while others braved the heat to find refuge in air conditioned malls or at the very least to try and cool down with a shaved ice.
Aiba and Nino, however, had been corralled into doing chores for Aiba's grandpa.
They were outside, and while Aiba survived wearing nothing but flip-flops and shorts, Nino persisted in the futility of keeping a shirt on as they washed Aiba's grandfather's faded blue Datsun wagon in the blistering haze. This of course meant that they were throwing soapy sponges at one another and vaguely slapping water across the car's shiny windshield, rather than actually being useful to the cleaning process. Aiba laughed high and loud, dodging quickly as Nino attempted to shoot a stream of water across the hood at him from his sopping rag.
Stooping, Aiba picked up the running hose. He focused the flow of the water with his thumb, the firm spray thundering across the metal of the car before managing to zap Nino in the shoulder. There came a cry of surprise and then laughter through protests of dirty fighting before Nino abandoned his side of the car.
Pushing himself up and onto the vehicle, Nino used the standing water to slide over the hood in a smooth motion Aiba couldn't help find really cool, even as he made to retreat along his side of the car. Unfortunately, he hadn't accounted for the fact that the hose could only travel so far.
Nino leaped off of the car, darting into Aiba's space to try and gain control of the hose. They struggled, spraying cold water across each other and the car as one tried his best to wrest the bubbling fountain from the other. Being nearly a full head taller, however, Aiba managed to gain control by backing Nino against the car, a fact he was going to count as a victory until a kink in the hose built up enough pressure for it to jerk violently. Slipping out of his hands, the boys slammed against the hood and Aiba braced himself from falling by grabbing the car.
Yelling and laughter came between attempts to catch their breaths and it was probably a full minute before Aiba realized his chest was still jackrabbiting with the beat of his heart, a fact that was no longer due to surprise or the instinct to combat an opponent.
Nino's thin white shirt was soaked through, his wiry frame thrown into stark relief as the saturated cotton clung to him like a second skin. His face was red from heat and laughing too much, and his eyes were bright with amused mischief. Water and sweat beaded at the ends of his dark hair, plastered against his forehead and neck in inky strands as rivulets of sunlight teamed down the lines of his face.
Aiba had an confusing—exhilarating—terrifying moment as he recognized the tightness in his chest and the flip in his gut. He was saved any awkwardness in disengaging, however, as he screeched with the shock of a large, heavy blob of cold sponge being forced down the front of his pants. Flailing about, Aiba tripped backwards over the hose around their legs and stumbled into the grass, trying madly to dig the unwelcome intrusion from his shorts as Nino collapsed against the car laughing.