"Renji," his mother says, her hands pressing down on his shoulders, "there's more to life than tennis, you know?"

Renji tilts his head to one side, the precise edge of his child's haircut swinging against his cheek. Behind him he can hear the shouts of the other children and the scuff of their feet against the dirt and the soccer ball. The tennis ball is soft in his hand, except for where bits of brick from the wall are stuck to the fuzz and scratch against his fingers.

"No," he answers, "I don't."

******

Minami-kun has a good backhand, and Ishida-kun can perform a successful smash on three out of four tries despite being only 8 cm taller than the net, but Renji finds Inui-kun's tennis much more interesting.

It's Inui-kun who arrives even earlier than Renji to practices, and Inui-kun who stays later, always working on something. Last week, their coach had given out a gentle suggestion that Inui-kun work on his serve after he'd double-faulted in successive games, and when Renji was sitting on the bench, swinging his feet and waiting for his mother, Inui-kun was still on the courts with a basket of balls.

At first virtually every other ball was smacking into the net, Inui-kun's arm already tired from practice. After a little while, only about every third ball was hitting the nylon, then every fourth, then every tenth, and finally Inui-kun had stopped when the thirty-fifth ball in a row hit the opposite fence.

Renji hasn't seen Inui-kun fault once since then.

Today Inui-kun is working on his forehand, driving the ball against the wall, the steady thwok-thwok turning to thwok-whiff as his racket meets nothing but air. The ball patters across the concrete past Renji, and he watches it go before turning back to Inui-kun, who already has another ball in his hand.

"There's nothing wrong with your forehand," Renji says.

Thwok-whiff goes the ball and Inui-kun's racket, and Inui-kun turns to meet Renji's gaze, glasses slipping down his sweaty nose and one eyebrow raised.

"Except for that weird thing you're doing with your left foot," Renji amends. "It's your timing."

Inui-kun frowns a little. He looks down at his racket, his sneakers, the basket of balls, the wall, and back to Renji. Finally he says, "Show me," and then adds, "please," after an awkward second. Renji bobs his head, hair swinging, and strides over to stand in front of the wall that Inui-kun's been hitting at.

"Hit at me instead," he says, bringing up his racket and settling into his ready position. "The wall isn't much for constructive criticism."

From this position, Inui-kun's problem is even more obvious, and Renji nods to himself. He's not doing anything in particular as he returns the ball, but by the third twang of his racket strings, the ball is hurtling at him noticeably faster.

"Slow down!" he calls, drawing his racket back to absorb some of the force of Inui's shot. "You aren't a dash specialist!"

Inui-kun blinks at Renji and the ball slams past him, whistling sharply through the air even after Renji's absorption of force. After a second Inui-kun laughs at himself.

"I'm not fast enough for my own tennis," he admits, running his hand through his hair and spiking it up even crazier than usual. "Sorry, Yanagi-kun."

Inui-kun says the vowels of Renji's name funny, flattened and run-together and different from everybody else.

"Oi, you two," the coach says, off to Renji's left, and he and Inui-kun both startle since they didn't notice him approaching. Renji lowers his racket and finds the coach with his arms crossed, frowning in gentle exasperation. "Don't you think it's time to give it a rest, hmm?"

"I want to play doubles," Renji announces without pre-amble.

He's usually a polite and cooperative boy, but he's been practicing this conversation in his head all week, so that when the coach begins saying something about holding tryouts, Renji interrupts and the words "Inui Sadaharu will be my doubles partner" roll off his tongue as easily as his own name.

As their coach chews on that for a second, Renji can hear Inui-kun's sneakers scuffing the court softly behind him.

"You say my name funny," Inui-kun says when their coach has left them to it. "What thing with my left foot?"

Inui-kun usually walks home, but today he sits on the bench beside Renji as they wait for his mother to arrive. The topic of Inui-kun's speed comes up again as they talk.

"My legs are too short," Inui-kun sighs, "no matter how much milk I drink."

"If you knew where the ball was going," Renji says, just thinking out loud, "it wouldn't matter."

A second later it catches up with Renji that any idiot could be a tennis ace if they knew where the ball was going all the time, but Inui-kun just scuffs the toes of his sneakers against the pavement and doesn't call him a moron, and Renji thinks they might be friends for life if Inui-kun survives being introduced to his mother.

********

"Your mother scares me," Inui whispers, glancing around furtively, and Renji blows his bangs out of his face.

"Inui-kun, that's not any kind of secret," he says, "much less your deepest darkest one."

"Your secret was that you don't like milk tea," Inui-kun retorts. "Are we best friends yet?"

"I'm not sure." Renji sits back on his heels and considers this. "We are having a sleepover. And we are in a blanket fort. But I don't know if those are conclusive criteria."

"Your criteria are completely subjective," Inui-kun says, then shoves a handful of baked wheat crackers into his mouth, which Renji knows, thanks to Inui's mother, have exactly 13 kilocalories a cracker. He chews and thinks for a few seconds. "What if we watch a movie that makes both of us cry and then never tell anybody else about it ever?"

"Hmm." Renji lets his eyes open just enough to examine Inui-kun's face for signs of teasing. "What movie?"

"Boys!" Inui's father calls suddenly from downstairs. "I'm back from the video store! The new Lucky movie is out!"

Renji hops to his feet and grabs Inui-kun's wrist to drag him out of the blanket fort.

"Look," Inui's mother whispers to Inui's father fifty-seven minutes later, clearly sharing Inui-kun's misconception about the volume of their whispers, "they're both crying! Cute!"

"Okay," Renji hisses, and Inui-kun swipes quickly at his glasses with his sleeve, "now we're best friends."

But he isn't really really sure until Inui refuses to take off his wristbands to go to bed and Inui's mother asks him in exasperation whether there isn't room in his head for more than one thing at a time.

*******

The week Inui-kun gets a slight sprain in his right ankle and can't play for two weekends running is the worst week ever, so far as Renji is concerned. Inui-kun still comes to practice though, watching Renji's matches with his ankle propped up on the coach bench and scribbling in the notebook Renji gave him.

Halfway through his third game Renji starts to frown, because Inui-kun does prefer to write down a completely ridiculous amount when a well-planned diagram would do just as well, but nobody has this much to say about doubles formations, which is what Inui-kun is supposed to be scribbling that notebook.

Not to mention, Inui-kun seems to be staring at Minami-kun instead of at Renji. Renji frowns harder and Minami-kun's serve slaps the pavement next to his right foot.

"Service ace!" Minami-kun shouts, half in glee and half in surprise, and Renji grits his teeth and does his best not to watch the twiddle of Inui-kun's pen or listen to the scratch of ink against paper, not to guess the shape of the kanji by reversing the arcs of Inui-kun's eraser through the air.

He isn't that much better than Minami-kun, not yet, his singles skills just this side of rusty in the face of his doubles obsession, and Renji's fractured concentration turns into "Set, Minami-kun, six games to three" not much afterwards. Renji wipes his palm across his forehead; Inui-kun's face is still buried in his notebook.

"What are you writing?" Renji demands after he's stomped over to Inui-kun. His chest feels tight and unpleasant, the loss twisting all up with the way Inui-kun looks up guiltily and slams the notebook shut.

"It's nothing, Yanagi-kun." Inui-kun is staring at his sneakers.

Just like Renji is staring at his when his mother comes to pick him up twenty minutes later.

"I don't feel well," he mumbles at her questions, and doesn't say good-bye to Inui-kun as he climbs into the car and slams the door shut. He can hear his mother and the coach talking in low voices, but keeps his eyes squeezed shut and rests his cheek on the rough material of his tennis bag.

*******

The next weekend, Inui-kun doesn't sleep over, and Renji's mother has to come get him out of bed so he makes practice on time.

When he gets there, Inui-kun is playing Minami-kun, and Renji's chest knots up even tighter, the juice and toast he had for breakfast sitting in his stomach like a rock. He wants to turn away, wants to go home, but then Inui-kun returns a cross-court shot that even Renji would have been two feet short of, and Renji's eyes widen in surprise.

Minami-kun seems just as puzzled as Renji when all his shots are being returned to him, by Inui-kun of all people, who is nowhere near him in the loose rankings they all exist in. Minami-kun steps up the pace, stepping deeper into his shots and driving them closer to the lines, but Inui-kun is always right in front of them, like magic, constant like physics itself.

Inui-kun can't have improved this much in only a few weeks, can he? Renji chews his lip and opens his eyes wider, looking for the trick. Renji himself is only better than Minami-kun by the skin of his teeth, and Inui-kun had been nowhere near that for all his hard work. It hardly seems possible, but Renji is seized by the sudden fear that Inui-kun will surpass him, suddenly out of reach like the smash that catches Minami-kun flat-footed and reaching in the wrong direction.

Everyone else is watching too, their own games forgotten, when Minami-kun's game falls apart, and Inui-kun wins 6-1.

"Did you see?" Inui-kun exclaims, bounding over to Renji and practically vibrating with excitement. Renji tries to answer, but can't swallow the lump in his throat out of the way, and Inui-kun just goes on talking like usual. "It was amazing! Even if Minami-kun hadn't fallen apart on his own, there was a 67% chance that I would have still won! It works!"

"Works?" Renji repeats. Minami-kun is still standing on the court, looking at his racket, and Renji knows exactly how he feels. "What works?"

"The data!" Inui-kun pulls his notebook seemingly out of thin air and flips through pages, voice fast and breathless like he's still playing. "You said it wouldn't matter how fast I was if I knew where the ball was going, so I wrote everything down and studied it all week and…"

Inui-kun cuts off abruptly, cheeks flushing pink and notebook not quite extended to Renji. He's…embarrassed? Renji is in no state to puzzle it out, and reaches for the notebook, feeling like he's stuck in some bizarro-verse dream where Inui-kun is a tennis ace and he's a blithering idiot.

The page Renji is looking at is labeled "MINAMI-KUN" in neat, blocky characters, and below is an endless string of notes like "forehand right → backhand right" and "mid-court lob → smash" all in a huge jumble.

"I wasn't sure what to do with it at first, so I just wrote down everything," Inui-kun is explaining, and reaches over to flip a few pages. "But when I sorted it out, this happened."

The next page features neat headings with names of shots, and underneath every shot hit in return, each with a percent in descending order, and Renji finally realizes that Inui-kun was keeping track of how often Minami-kun returned a certain kind of shot with a particular shot of his own.

It was clunky, and time-intensive, and would complicate exponentially when opponents used more advanced tennis but…

"Forehand to the left," Renji reads to himself, Inui-kun's game playing back in his head, "and Minami-kun will return with a cross-court right 89% of the time…that's how…you didn't improve, you just…" Renji cuts off suddenly in the middle of his accidental insult.

Inui-kun doesn't seem to notice. "I just moved to the spot where he was most likely to return it. The destructive psychological effects were just a happy coincidence."

Inui-kun sounds psychotic, and Renji can't stop grinning. "It's good," he says. "It's good data."

"It needs work," Inui-kun says, but he's bouncing on the balls of his feet. "There's too many variables, and tennis is too fast to record everything properly, but if you had, say, a video tape…"

"It's too confusing like this," Renji says, cutting off Inui-kun like normal, and he realizes that the tight knot in his chest has fallen apart like Minami's game. "You can't see the patterns when it's all jumbled. You need…" Renji fishes down in the side pocket of his bag and comes up with a green pen. He tucks it into Inui-kun's hand. "Here, let's color-code them, Inui-kun. We can start with the forehands to the left and…"

"Sadaharu," Inui-kun interrupts, making Renji blink. Inui-kun's cheeks are just a little pink again, and he tilts his head so Renji can't exactly see his eyes for the glare of the sun off his glasses. "It's Sadaharu. We're partners, aren't we?"

Renji tilts his own head so Inui's silly trick won't work on him and he can see the uncertain green of Inui-k—no, of Sadaharu's eyes. "Sadaharu-kun. It's Renji."

"Just Sadaharu," Sadaharu corrects, grinning like an idiot, and Renji punches him in the shoulder.

Sadaharu punches him back, green pen clenched tight in his fist, and then they have a fight over whether the Hamtaro notebook is professional enough to contain their data until their coach separates them and makes them run laps.

******

They're on their stomachs in Renji's living room, feet kicking the air and the new Kamen Rider on the television. Renji is working on the data for next week's game, which will be their fifth consecutive win if Sadaharu doesn't break his spine lugging around all his notebooks; he's already got eight compared to Renji's three.

"I've worked it out," Sadaharu says abruptly, and Renji gives a soft 'mmhmm' without looking up. "It will be optimal if we start liking girls .63 of the way into our second year of junior high."

"Is that so?" Renji says, not even bothering to strip the amusement out of his voice, because Sadaharu is already rambling on about growth spurts and hormone levels and cheerleading uniforms.

He sneaks a glance over at Sadaharu's notebook just to be sure: tennis is still written in green, girls are written in lavender, the shade of the new sweater that Sadaharu's mother just bought him and that Sadaharu hates violently.

So everything'll be just fine, then.

"Eight times a week," he agrees, repeating Sadaharu's words without listening very deeply, and he steals the green pen back to label this week's match "Yanagi-Inui vs," then drops it to grab another color for the opposing pair.

It's the lavender, he realizes as he squares off the first character in "Atobe," and wonders why that seems so fitting before he gets distracted by Sadaharu trying to sneak a new move into their data called the "Super Inui Special."

"Stay over tonight," he says after they're done wrestling, the remote jammed into the small of his back, but he doesn't move because Sadaharu's head is on his stomach, glasses askew and head looking like a startled pineapple. Sadaharu is humming the Kamen Rider end theme tunelessly along with the television, but he stops to tilt his head backwards and grin at Renji upside-down.

"Renji," he mother says while Sadaharu is on the kitchen phone, bouncing on the balls of his feet and trying to be louder than Inui-san, which is impossible. "Don't you think Inui-kun might want to spend time with his other friends sometimes too?"

Renji pulls two cups of Yan-yan out of the cabinet, chocolate for him, strawberry for Sadaharu, and grins to himself when he hears Sadaharu tell his mother that no, Hello Kitty notebooks are not acceptable.

"No," he says, shaking his head hard enough that the precise edges of his child's haircut flare, "I don't."

******
Epilogue
******

"So, Sadaharu," Renji says immediately after their fifth consecutive win, "I've been thinking we should practice kissing."

Renji's eyes are closed, the grip tape sticky against his palm and the sun warm on his face. He takes a moment to listen to the crowd still cheering for them, Inui's mother yelling loudest of all, before he turns to find Sadaharu's eyes fixed on him.

Renji is hoping for surprise on Sadaharu's face, he even opens his eyes enough to see it, but just this once he's disappointed.

"For girls?" Sadaharu asks, voice 23% amused and 77% breathless, presumably from the match. "My data indicates that three to four practice sessions will be sufficient before the introduction of tongue and/or light petting."

"Good," Renji laughs, gripping his racket until his knuckles are white because his chest is full of data and Sadaharu and tennis, and he isn't disappointed at all.