A/N: more copied author note:

In which it is exceedingly obvious that the author has no idea how to play shogi and did not actually google it before writing the chapter because the Learning Brain is different from the Writing Brain and they do not trigger simultaneously.

Takes place during chapter 68, lining up with the end of it.

Writing geniuses is still hard. even when the genius in question is shikamaru instead of kakashi. shikamaru would never be so undignified as to use the word Rival to describe anyone. Too Troublesome.
But also.
He is rather short of good words to describe how much vexation and intermittent rage natsu induces in him though.
I think you would call this "helping with malicious intent" XD
As always, thanks for reading and hope you enjoy!

Shikamaru doesn't quite haunt the hospital. His wrist is still in a brace, if anyone asks he's here for a checkup- it's a surprisingly effective excuse, mostly.

The secretary doesn't buy it, but she's a Yamanaka, so she doesn't say anything either. He used to use the excuse of checking on his dad, right up until his dad heard about it and started making him run messages, ugh, troublesome, so…

His dad should be released soon, at least. Then someone else can deal with all mom's bossiness. Sure, tending the forest and taking care of the damaged but not destroyed parts is important, but…

Well.

As far as Shikamaru's concerned, he shouldn't be the one doing that.

So… he's not quite haunting the hospital. Maybe he should dolly it up, make like a mission report.

0740, undercover stakeout. Target is expected to arrive within the next two hours-

Current status: on track, no trouble detected.

Shikamaru settles himself at one of the lounge room shogi boards, takes a deep breath, and invites the first person he lays eyes on to a game.

It passes far too quickly, as do all the others he invites people to, but… it's not about the games, really.

It's about the people. Most of them don't speak, and even the ones who do, tend to be grateful when he makes it clear they don't have to hold to social norms. A couple shinobi talk shop with him, one even throws the game, Shikamaru glares at his back as he cheerily whistles his way out the doors-

Shikamaru puzzles through that game, and that man, all through the next two matches - civilian with a shinobi son, likely badly injured in the fighting if he's still in the hospital… shinobi, recovering from poison, or maybe a bad lung injury, here for a checkup…- when he finally catches sight of his target.

Natsu attempts to lean against the secretary's desk, fumbles awkwardly when he realizes he's too short, and hastily laughs it off while asking if Sasuke's checked himself out yet or not, because he'd thought he would, but then he wasn't home, so he figured he'd check…

Shikamaru laughs a little, idly making the next play as plans and possibilities flicker, born and dead in moments. He expected the arrival but not the reason, doesn't know where Sasuke is ̶-̶o̶r̶ ̶d̶o̶e̶s̶ ̶h̶e̶?̶ ̶S̶a̶s̶u̶k̶e̶'̶s̶ ̶a̶l̶w̶a̶y̶s̶ ̶b̶e̶e̶n̶ ̶p̶r̶e̶d̶i̶c̶t̶a̶b̶l̶e̶,̶ ̶a̶n̶d̶ ̶h̶e̶'̶s̶ ̶n̶o̶t̶ ̶h̶e̶r̶e̶ ̶i̶n̶ ̶t̶h̶e̶ ̶h̶o̶s̶p̶i̶t̶a̶l̶,̶ ̶b̶u̶t̶ ̶a̶l̶s̶o̶ ̶n̶o̶t̶ ̶h̶o̶m̶e̶.̶ ̶U̶n̶d̶o̶u̶b̶t̶e̶d̶l̶y̶,̶ ̶a̶l̶s̶o̶ ̶n̶o̶t̶ ̶a̶r̶o̶u̶n̶d̶ ̶a̶n̶y̶ ̶o̶f̶ ̶h̶i̶s̶ ̶u̶s̶u̶a̶l̶ ̶t̶r̶a̶i̶n̶i̶n̶g̶ ̶g̶r̶o̶u̶n̶d̶s̶,̶ ̶a̶s̶ ̶N̶a̶t̶s̶u̶ ̶w̶o̶u̶l̶d̶ ̶h̶a̶v̶e̶ ̶c̶h̶e̶c̶k̶e̶d̶ ̶t̶h̶o̶s̶e̶ ̶b̶e̶f̶o̶r̶e̶ ̶h̶e̶ ̶e̶v̶e̶r̶ ̶b̶o̶t̶h̶e̶r̶e̶d̶ ̶c̶h̶e̶c̶k̶i̶n̶g̶ ̶t̶h̶e̶ ̶h̶o̶u̶s̶e̶ ̶t̶o̶ ̶b̶e̶g̶i̶n̶ ̶w̶i̶t̶h̶…̶ ̶H̶e̶ ̶r̶e̶c̶e̶n̶t̶l̶y̶ ̶h̶a̶d̶ ̶a̶n̶ ̶e̶n̶c̶o̶u̶n̶t̶e̶r̶ ̶w̶i̶t̶h̶ ̶h̶i̶s̶ ̶b̶r̶o̶t̶h̶e̶r̶ ̶t̶h̶a̶t̶ ̶h̶i̶s̶ ̶s̶e̶n̶s̶e̶i̶ ̶s̶t̶i̶l̶l̶ ̶h̶a̶s̶n̶'̶t̶ ̶r̶e̶c̶o̶v̶e̶r̶e̶d̶ ̶f̶r̶o̶m̶,̶ ̶a̶n̶d̶ ̶e̶v̶e̶n̶ ̶m̶o̶r̶e̶ ̶r̶e̶c̶e̶n̶t̶l̶y̶ ̶h̶a̶d̶ ̶a̶ ̶d̶i̶s̶a̶s̶t̶r̶o̶u̶s̶ ̶m̶e̶e̶t̶i̶n̶g̶ ̶w̶i̶t̶h̶ ̶I̶n̶o̶'̶s̶ ̶d̶a̶d̶.̶ ̶P̶o̶s̶s̶i̶b̶l̶y̶ ̶i̶n̶ ̶r̶e̶l̶a̶t̶i̶o̶n̶ ̶t̶o̶ ̶h̶i̶s̶ ̶r̶o̶l̶e̶ ̶a̶s̶ ̶h̶e̶a̶d̶ ̶o̶f̶ ̶T̶ ̶,̶ ̶b̶u̶t̶…̶ ̶t̶h̶e̶ ̶w̶a̶y̶ ̶d̶a̶d̶ ̶r̶e̶a̶c̶t̶e̶d̶ ̶w̶h̶e̶n̶ ̶h̶e̶ ̶h̶e̶a̶r̶d̶ ̶a̶b̶o̶u̶t̶ ̶i̶t̶…̶ ̶m̶a̶y̶b̶e̶ ̶a̶c̶t̶u̶a̶l̶l̶y̶ ̶i̶n̶ ̶r̶e̶g̶a̶r̶d̶s̶ ̶t̶o̶ ̶h̶i̶s̶ ̶r̶o̶l̶e̶ ̶a̶s̶ ̶a̶ ̶l̶i̶c̶e̶n̶s̶e̶d̶ ̶t̶h̶e̶r̶a̶p̶i̶s̶t̶?̶ ̶A̶n̶d̶ ̶e̶v̶e̶n̶ ̶w̶i̶t̶h̶o̶u̶t̶ ̶b̶o̶t̶h̶ ̶o̶f̶ ̶t̶h̶o̶s̶e̶,̶ ̶S̶a̶s̶u̶k̶e̶'̶s̶ ̶a̶l̶w̶a̶y̶s̶ ̶b̶e̶e̶n̶ ̶s̶o̶ ̶r̶e̶c̶k̶l̶e̶s̶s̶,̶ ̶w̶h̶i̶c̶h̶ ̶m̶e̶a̶n̶s̶ ̶h̶e̶'̶d̶ ̶p̶r̶o̶b̶a̶b̶l̶y̶…̶ ̶y̶e̶a̶h̶.̶ ̶A̶n̶d̶ ̶t̶h̶e̶ ̶t̶i̶m̶e̶ ̶m̶i̶g̶h̶t̶ ̶c̶h̶e̶c̶k̶ ̶o̶u̶t̶,̶ ̶h̶e̶ ̶l̶e̶f̶t̶ ̶s̶h̶o̶r̶t̶l̶y̶ ̶b̶e̶f̶o̶r̶e̶ ̶I̶ ̶c̶a̶m̶e̶ ̶i̶n̶,̶ ̶I̶ ̶w̶a̶i̶t̶e̶d̶ ̶f̶o̶r̶ ̶t̶h̶a̶t̶,̶ ̶s̶o̶…̶but then again, when it comes to Natsu, well. Even if he's wrong, it's never really about what he knows, like it used to be with Sakura. Just in how he presents it.

He hasn't spent much time with the interloper, but he's spent enough.

"He stopped by his house briefly," Shikamaru muses, just loud enough for his voice to carry, "though he left soon after. I guess I could tell you where to find him, but you don't really need to worry about it, so that seems like too much work."

Shikamaru fights to keep the smile off his face as Natsu squawks in protest. "It's not about whether I need to, it's about whether I want to! Where'd he go?" he stomps over then, body language a rictus of uncanny valley to anyone who's ever known Sakura. She'd stomp when angry, but Natsu isn't angry, just annoyed, and everything's just- off.

Ever so slightly off.

Shikamaru has tragically spent more than enough time around Ino to know.

He nods to his opponent just as the man starts to ask, and the shinobi barks a laugh as he gets up from the table. Hmm. An Inuzuka without markings? Married in-? No, the bark is too distinctive-

Ah. ANBU Mantis has a ninken partner, and they were wearing black- not telling in and of itself, but with the lack of clan markings… Interesting. So-

"No, come on, stop messing with your board, can't you just tell me where he is? I know you don't like me, I'll get out of your hair if you do!"

It's not quite a whine, though the annoyance is a little more clear that time. And yet it's not as aggressive as Shikamaru might have expected, either. Well. That just makes things easier for him.

"Mm," Shikamaru muses as he sets the last piece down, "If Natsu wants to run away from a challenge, that's fine. He can look for Sasuke himself, then. Or… he can play a game, and I'll tell him where to find his teammate. I think we both know which of these would be faster."

Shikamaru doesn't usually bother with pettiness. Too troublesome by far, and far more work than just avoiding whoever's upset him. But, watching the way Natsu twitches, torn between the multiple layers of insult-

It's a little delightful.

Natsu's not actually stupid, is the thing Shikamaru's noticed. If anything, he's almost terrifyingly perceptive. Not much of a strategist, but a powerhouse who gets people. The kind of person who almost doesn't need to be good at strategy, because their instincts are just that sharp. Natsu knows there's a trap here.

Shikamaru's not much of a sensor, nothing compared to Ino, really. But Naruto's always stood out to him in a way that's impossible to miss. Natsu's physical senses may be on par with an Inuzuka's, if not better. But he can't sense chakra, and Shikamaru would bet good money that Hatake Kakashi never actually taught him the basics of sensing, even just to the level of the Academy courses.

…if Hatake-san even knows what the basic Academy courses teach to begin with, considering how quickly he tested out.

Either way-

It puts him at an advantage, because Natsu knows there's a trap, spectacular instincts on full display, but cannot even begin to guess the shape of it.

Shikamaru can't sense Sasuke, can't really sense anyone other than Naruto and maybe his team if he focuses at range. But he knows how Naruto and Sasuke have been, since the beginning. Naruto will deal with Sasuke's ill-thought recklessness.

And also act as Shikamaru's own beacon to Sasuke's location.

So he can tell Natsu things like you don't need to worry about Sasuke and I can tell you where he is, and be 100% truthful.

And since he knows Shikamaru isn't lying, he'll stay, which means Shikamaru can ̶t̶o̶r̶m̶e̶n̶t̶ help his ̶p̶r̶e̶y̶ ̶comrade by forcing him to actually think, and work through Sasuke's actions for himself.

Natsu sits down with a huff.

Shikamaru immediately takes the first move. It's not his usual style, and he doesn't like it, prefers to let his opponents go first to get a read of them, and their mood, but he's played just enough with Natsu to know-

Natsu hates it when he just takes initiative without so much as acknowledging it.

It's not pettiness, it's just… hmmm… training, perhaps?

The scowl Natsu sends him is as amusing as it was predictable, and Shikamaru makes sure to put in the effort to smirk back. "So, imagine that you're Sasuke," he starts, as Natsu shoves a piece forward. It looks random, probably is, even, with that huffy posture and sharp jab at the piece itself, but… it's actually a pretty good move.

And therein lies the dichotomy of Natsu. That fascinating puzzle that makes games with the man so fun, even though Natsu himself is rather something of an antithesis to Shikamaru's entire creed. And also the cause of 90% of Shikamaru's current workload.

He's a dichotomy between cleverness and carelessness. Natsu makes tactically sound decisions in nearly every single play. But he never has an overarching strategy, never really bothers to lay traps or try long-con maneuvers. A truly spectacular instinct for reading a situation and judging responses in the moment, tempered by a lack of patience and an equal lack of desire to exercise forethought, ever. He might even be allergic to it, actually.

Pieces go back and forth across the board, as Shikamaru sets up an elaborate play. Average players would probably lose to Natsu quite a bit, he's pretty sure. Natsu's just good at making good calls. Pretty good at worming his way out of traps through unorthodox plays and off-the-wall thinking. Hard to predict, due to never actually bothering to plan any of his moves, which almost makes him better at playing against Nara and their love of pattern recognition and prediction, than most other people.

But then again, knowing that Natsu's sharp instincts and ability to read a room often have him taking the best escape out of any given trap, well.

It's an interesting challenge, at any rate.

And one he's succeeding, because Sakura's ride-along spirit hasn't won a single game off him yet.

Case in point-

"What- come on! Don't just say that and then go quiet! Are you seriously going to make me figure out where Sasuke is? Why can't you just tell me?"

The lack of patience really does wonders on his behalf. Natsu moves one of his pieces out of Shikamaru's line of fire, scowling across the board.

Right where Shikamaru wants him.

"Well, he's your teammate, isn't he? Maybe Team 7 does things differently, but in Team 10, we value understanding each other."

"I understand Sasuke just fine!"

"And yet you don't know where he is? I barely know him, and it's still more obvious than the Hokage Monument. It only took a couple of seconds to work it out. Are you saying I know him better than you?"

Natsu splutters, head tilting, and Shikamaru wonders what Sakura has to say to that. "Wha- the- that's not what I said at all!"

Shikamaru bites back the smirk this time, but… not as subtly as he could. Lets it show that he's trying to hide it. "Consider this an exercise in team bonding then, yeah? You guys have done lots of teamwork missions since graduation, so it should be an old hat for you." Shikamaru makes the next play, then continues, "You're Sasuke. Your brother previously murdered your entire family, and personally tortured you. Said brother has recently reappeared in the village, where he proceeds to attack one of your teammates, put your sensei into a coma, and then tell everyone that the only reason he did all of this was to target your other teammate."

"Yeah I know all that, I'm not stupid." Natsu bites out, annoyance starting to shift, impatience mixing to twist to anger, but his play on the board is as well-made as all the others.

Anger doesn't tend to drive Natsu to make mistakes, though Shikamaru's never really riled him up into anything further than the first fringes of it, where annoyance turns to upset turns to the first stirrings of shut the fuck up and tell me already. It's still impressive, even on this level, how unblinded Natsu is by his own emotions. A lot of shinobi would be jealous of that, honestly.

"Do you really?" Shikamaru needles, "Because shortly after this event, he goes to Yamanaka Inoichi, a mindwalker, to confront memories, I am assuming of his brother's past actions, though admittedly I don't know that for certain. What I do know, is how badly that ended. And you do too. So… what would you do, in that position? A dead family, your new family being threatened by the same man who killed the first, and now you try and get help but instead make everything worse- isn't it obvious?"

It's not easy to lead Natsu along any one train of thought. He's tragically un-horse-like, in that regard. Or maybe just chronically allergic to water. Shikamaru wouldn't put it past him. His impatience gets the better of him, and he'll often charge right past whatever point Shikamaru is trying to make and miss it all entirely if it isn't spelled out quickly enough.

Shikamaru's no master of wrangling Natsu's thoughts, but… he'd like to think he's getting the hang of it.

Natsu huffs. "Well I don't get it, actually, because if all that happened to me I'd be right here!"

Shikamaru tilts his head, a deliberate tell of doubt, as he ponders that. Would Natsu really just stay in Konoha? He hasn't really shown any degree of loyalty for anyone outside of his team, and he has shown a degree of recklessness that should nominally…

"Catch you off guard?" Natsu leans back into the couch, arms crossed, as he grins smugly at Shikamaru. That- did he realize Shikamaru was baiting him into getting angry this time-? "Hah! Take that, you Kageyama wannabe! Of course I'd stay here! Naruto's currently with Jiraiya, and some lady who Sakura-chan swears is even stronger than him, and I'm inclined to take her word for it. Any brother of mine would have to be an absolute idiot to go after him right now! Obviously I'd stay back here, with Kakashi-sensei, since he's the one in the most danger, just in case anyone came back to try and finish the job. And then, once Naruto makes it back and we're all together again, I'd go hunt down Gai and Jiraiya and maybe that cool chick with the dogs, she seemed pretty strong too, and I'd make them help me hunt my hypothetical idiot of an older brother down so I could beat his face in and get him to stop being so stupid. Duh!"

One of Natsu's hands come up to his throat and then immediately back down. Shikamaru files away the odd gesture as he puzzles through that. There's not a lot of women who could be considered stronger than Jiraiya, and only one Shikamaru can remember Sakura ever idolizing. He hadn't realized Naruto was traveling with Senju Tsunade, only that he was out on an extended mission with Jiraiya. Interesting…

But more than that-

Note to self: Natsu is not good at empathy experiments.

Shikamaru laughs as he cuts off Natsu's last battalion and takes the game in one final play. "Well, I guess that makes you smarter than Sasuke in this one singular instance. Because Sasuke is half-way out the village right now, planning to go after his brother alone." He sticks his leg under the table and stops Natsu from standing, "You don't have to worry about running out after him though, because Naruto made it back to the village approximately fifteen minutes ago, and is handling it. So."

Shikamaru resets the board, jerking his leg and sending Natsu crashing back into the couch with the motion. "Why don't we go again, and I'll explain to you why your decision to leave Sasuke alone in the hospital earlier this morning was, in fact, the stupidest possible thing you could have done in the moment. Shall we?"