Somehow, it had become important for him to know.
Nagisa already knew, of course he did - with that annoyingly cheerful grin as he still insisted on calling her "Gou-chan!" Because, after a little while, she had already given up on correcting him and just went with it, albeit with a deeply exasperated sigh and side-eyeing him a little. In a completely friendly manner. Of course.
With Makoto, she made sure to hand him things carefully, juice-boxes and towels - and looked him fully in the face and eyes, with the whole of her apt attention. She knew, as an older brother, how some things passed him by first.
Rei, she instructed brashly somewhat but her glowing enthusiasm and encouragement was so very apparent. Especially with the reminder-signs she diligently hand-painted and posted up every day.
So, one day, she sidled up to him as he straightened his tie and pulled on the strap of his backpack. Makoto-senpai was standing a little away, gently trying (the operative word) to ward off Nagisa-kun who was – and, there was no other way of saying it - harassing Rei-kun. The latter of which was flailing a bit desperately now as he backed away, but she ignored this. Determinedly she tugged at his shirt sleeve, where it rested above a finely-pointed elbow. He turned, inclined his head a bit, blue eyes settling firmly on her own red ones.
More than her appreciation of his form, in swimming and his physical body, more than any other under-laying hopes and intentions, she wanted him to know-
"I like you."
Haruka-senpai blinked as she smiled up at him.
Because, really, that was all that need to be said.
AN: I'd really wanted to write a HaruGou (to cheer me up from EPISODE 7 AND FEELS) but this turned out more friendshippy and Gou/Iwatobi!boys. Gosh, Haru - just, ALL MY LOVE FOR YOU BBY! *sobs