Talk no Jutsu (also known as Therapy no Jutsu), commonly abbreviated as TnJ, is Naruto Uzumaki's strongest jutsu. Using it, he can talk to the most evil, depressed, monstrous, horrible person and make them change their entire life's ideology in a matter of minutes.
This jutsu was taught to Naruto by his mentor Iruka Umino when he tried to save Naruto even though Naruto was blamed for his parents death. TnJ also seems to be Iruka Umino's only jutsu. In chapter 655, it is revealed that Naruto's mother, Kushina Uzumaki, also had a talent for TnJ, but it does not disclose to what extent Kushina can control this jutsu. It is hinted that Hinata Hyuga also has an act for TnJ, this can be seen after Neji's death and Naruto began questioning himself. Each TnJ can be activated by simply a word from the person and if the word is used again and again, the controlled person falls deeper. Naruto's activating word is Dattebayo while Kushina's word is Dattebane. Iruka's activating word is obviously the word Naruto. Boruto's Dattebasa may also be a hint that he has the talent to use TnJ.
Naruto first used this jutsu against Zabuza Momochi. He said a few sentences about how Zabuza shouldn't treat Haku like a tool and then Zabuza started crying because of it and got himself killed.
After that, Naruto used TnJ in the Chunin Exams against Neji. Naruto continuously used small bits of TnJ on Neji throughout the fight and then blasted a TnJ-enhanced uppercut punch right up at him. Then, when Neji was lying on the ground defeated, Naruto slipped in a little bit more TnJ to finish him off. By the time Neji was taken to get healed, the TnJ had already taken effect.
Naruto next used TnJ against Gaara. At first it didn't work, so he had to fuck it into him with a TnJ enhanced headbutt. The TnJ seems to be transferable as Gaara gained the TnJ ability after his encounter with Naruto though he still had a lot to learn as his TnJ was still underdeveloped. He gained for control at the Five Kage Summit when he asked the other Kages, "When did you forsake your yourself?" He also utilized it during the war when inspiring the other ninja and speaking to the reanimated. Unfortunately his TnJ failed miserably against Sasuke, who was just too emo.
The next usage was against Nagato. Normal TnJ didn't seem to work so he created a new variant of it called Sage Art: Talk no Jutsu and Sage Art: Flashback no Jutsu. This new TnJ variant, fueled by the natural energy of the earth, was so strong that it made the pure evil, baby-killing, nuke-making Nagato turn into a sissy Naruto fanboy and kill himself to revive all the people he had killed in his invasion on Konohagakure.
Naruto used TnJ to Killer Bee to make the latter train him. Sadly, it didn't work. Hence, Naruto invented another strong variation of TnJ called TnJ: Brofist no Jutsu. This variation is a special one since it did not contain the toxic dialogue of merchandising. He also did a little Rap no Jutsu to convince the rapper Killer Bee and worked like magic.
Naruto told the bloodthirsty Kyuubi that he'll "do something about his [Kyuubi's] hatred". Apparrently, the Kyuubi is not convinced a bit, since TnJ doesn't work to him, hence Naruto did what he's really good at - Action-speaks-louder-than-talk-no-jutsu (ASLTTnJ), shown by rescuing Kyuubi's fellow tailed beasts.Since then, the Kyuubi unquestionalbly joined forces with Naruto for another power up. Currently Kurama, the name SO6P gave to the Kyuubi, and Naruto are on first name basis.
Obito Uchiha, is the only known Uchiha to be TnJ-able by Naruto but was at first unable to work and ends up strangling Naruto. So Naruto developed Punch no Jutsu, bringing Obito to a new level of TnJ and being TnJ-ed by himself. With the combined power of Sage Mode and Tailed Beast Mode, Naruto unlocked a new wallpaper for his TnJ, a wallpaper so powerful not even the parallax wallpapers of iOS 7 can defeat. It seems that Naruto enhances his Talk no Jutsu with Flashback no Jutsu, a variant of the mother jutsu which usually accompanies the former. Obito, in this case, was punched so hard that he was put into flashback and started to TnJ on himself.
Nevertheless, At first it looked like Naruto's Talk no Jutsu pales compared to Hashirama's. The latter's Talk no Jutsu seems to be the most effective, converting Sasuke and Orochimaru to the good side, something that even Naruto could not do. The Talk no Jutsu is strong within Hashirama [though Naruto takes the limelight eventually towards the end when Hashirama's goes back to Netherworld]. Though Hashirama dosent know Sasuke really has a very different idea of hokage , like REALLY DIFFERENT.However Sasuke instead TnJ on Hashirama, so the Hokage blindly supported him ignorant of Sasuke's updated ideology of what the Hokage really is!
Itachi Uchiha has a variant of the technique called Izanami which traps the opponent in an endless timeloop until the victim is TnJ-ed by the illusion, due to this Kabuto turned good. It is also implied that Kakashi has now acquired a fair control of this jutsu. There is a chance the he has copied it using his sharingan. Nevertheless, Kakashi's TnJ is still underdeveloped as he cannot convert Obito to the good side during his mortal fight with him, leaving the job to Naruto. Instead, because Kakashi talks too much, he gets distracted and gets himself pierced while Obito teleports himself away, leaving a wounded Kakashi in the middle of nowhere.
Several people who have been noted to fall for Talk no Jutsu include Tsunade, a legendary Sannin who was converted into becoming Hokage and put into multiple flashbacks until she could hardly grasp for breath. Tsunade fell for TnJ so hard that she became almost Naruto's fangirl, placing her utmost important treasure and faith in him and even got herself almost killed by Orochimaru to protect him.
Despite the seemingly all consuming power of TnJ, there are a few ninjas who have shown resistance to it. These people include Uchiha Obito, Orochimaru, Uchiha Sasuke, Uchiha Madara, Haruno Sakura, the fourth Raikage, and Boruto Uzumaki.
However, Obito succumbed to Naruto and Kakashi's TnJ when he got convinced by how many Flashback no Jutsus for how many chapters/episodes which emphasized how Obito's senpai noticed him.
Sasuke, probably through his new sharinnegan was able to overcome the powerful jutsu by Hashirama. This is possibly because he is Indra's descendant and therefore extremely resistant to TnJ, similar to Madara.
Sasuke being a character who gets the last laugh, apparantly just appeared to be TnJ-ed by Hashirama, but to everyone's surprise, Sasuke himself used an advanced form of TnJ on Hashirama which made Hashirama and even Tobirama support him without even knowing that it was them who got TnJ-ed instead of Sasuke, but Naruto will kill Sasuke and become hokage! Believe it!
Now Sasuke is currently locked in the Talk No Jutsu dimension, only God can help him now. Through the many years of TnJing naruto is finally reaching a close after both naruto and sasuke developing such strong powers in TnJ they where able to communicate telepathically in their final fight. After much explosions and fighting both are now on the ground near death. This was when naruto activated his final, most lethal jutsu: TnJ Blood ties. By mixing his blood together with sasuke,despite their near death situation and the fact they are missing a limb, TnJ Blood ties allowed Naruto to completely brainwash Sasuke with no way of dispelling! TnJ has great effect from both Naruto and Sasuke. Sasuke is affected by this jutsu and ends up marrying Sakura , admitting that he accepts naruto as his rival his equal and best freind . VSR
Madara Uchiha is the only shinobi known to be able to resist such a powerful technique probably due to the fact that he created a counter jutsu to it in his time in the cave. The Give No Fuck Jutsu which can cancel the Talk no Jutsu which only Madara is capable of using to its fullest. Though normal TnJ does not work on him, Self Sacrifice Talk No Justu, SSTnJ, seemed to work for a couple years, when Hashirama almost took his own life and offered the position of Hokage to him. But in the end he was still strong enough since Indra reincarnation, and Hashirama was forced to "kill" him.
Madara once being Indra's reincarnation unknowingly learned a portion of the Justu from the latter while it was in its early stages. Indra's counter Jutsu was said to be called the Batshit No Jutsu which was accidentally created when he didn't get proper puppy love and daddy's attention.So he was willing to kill the Father of Shinobi, the Sage of Six Paths, and his brother Asura because he was not chosen as the successor to Ninshu. Indra didn't even wait an hour after the decision and decided to declare war on the two, and continued his fued until his death.
Apparently, the TnJ can be passed on to the next generations. There's reason to believe that Boruto Uzumaki is also able to use the fearsome jutsu, as he may have used it on Sumire Kakei, when the latter wanted to destroy Konoha by summoning the beast Nue. Not only did he change Sumire's mind, but Nue was also turned from rampaging beast to loyal puppy. There were signs before this incident, as Boruto's "dattebasa" was a hint to his hidden potential for using the TnJ.
The mechanisms behind the inheritance of the TnJ are not completely understood yet, which leads us to the question: does Himawari Uzumaki also have the hidden talent to develop the TnJ? Some say it's a kekkei genkai, but no confirmations have been made yet.