This story is the product of the PoT crack generator, which gave me Kikumaru Eiji/ Mukahi Gakuto Fuji Syuusuke. Somehow am incapable of writing crack, so this will be a multichaptered, vaguely angsty story instead.
It is Fuji's fault that Kikumaru Eiji is sitting in a café on a lovely Saturday morning, aimlessly stirring his strawberry milkshake and feeling bored out of his mind. The sunlight slants in through a lattice over the window that is all curlicues and delicately wrought flowers, makes a funny shadow on the ground that Eiji amuses himself with by imagining how one could contort to make that shape, the one that looks like a figure with back arched and a leg fully extended perpendicular to the ground; or the one that looks like someone trying to chew on his own knee whilst in an arabesque.
He wonders, idly, if he would have been able to make shapes like those if he had stayed long enough in Gymnastics. When he was ten he overheard his parents talking in low, hushed voices: caught the words 'flighty' and 'Eiji' in the same sentence, tinged heavily with worry, disapproval. They never actually said as much to him, but he was infamous by then for the way he switched clubs in school, brief stints that amounted to nothing, mere dabbling without focus.
That was until Gym came along. For a while he'd thought that this was something that would abate the constant restlessness that never stopped, a festering worm in his mind; the urge to keep trying to be a just a little closer to the sky and the sun and the stars was almost overwhelming. And he knew he was good at it - but being simply good was never enough, there was no challenge in escaping mediocrity. He lay awake at night, imagined the endless darkness above, wondered about the end to the stars he could jump to, zigzagging trails of stardust across the universe.
The weight of expectation (his own: he wasn't going to stay because he wouldn't be brilliant enough) kept him grounded, in the end.
Now he's in tennis because at least there if he isn't the best he's at least one of the top nine in the club, for sure, and therefore necessary to a certain degree.
Plus his acrobatic tennis was pretty much unique to him, at least until stupid Mukahi Gakuto of Hyotei decided to appear, with as much genius in gymnastics as Fuji had in tennis.
Eiji wishes he had just stayed being brilliant in gym, wishes it so hard that he's unwittingly clenching his fists, leaving indented red crescents in his palms.
The next thing he knows his handphone's vibrating with a message from Fuji and (more importantly) the object of his ire has waltzed into the café, a swish of mulberry-hued hair and pixie-sharp features.
The two are an impossible coincidence, given the timing.
"Why, Kikumaru-kun, such a surprise to see you here, ne." Mukahi drags the ki syllable sound slightly, and the way he drawls Eiji's name makes it sound like an insult.
Eiji forces himself to smile, because Tezuka will be unhappy if stories get back to him about unsporting behaviour, and he doesn't want to be running laps for the rest of his junior high life.
Mukahi taps a pale finger against his lower lip pseudo-pensively. "Such a curious thing, you know, Yuushi said he would meet me here but he just texted to tell me that he can't make it after all, he has a practice friendly with Fuji Syuusuke."
It occurs suddenly to Eiji that perhaps Fuji's logic stems from experience; Oshitari Yuushi is acknowledged to be a tensai almost of Fuji's caliber, the only other boy who can perform Higuma Otoshi as perfectly as Fuji himself (of course they hardly have similar hair colours, but that is really of peripheral importance)
Now the only unanswered question is which of the two cooked up this demented scheme.