Addressed as 'Yamamoto' by almost everyone in the series, this baseballer-turned-mafia has a warm and friendly personality and is rarely seen not smiling. He is, however, very naive to the point of believing that Reborn's weapons are advanced kid's toys and that the mafia business is one big cops-and-robbers game. Yamamoto is regarded by various Reborn characters, especially Tsuna, as being reliable and almost never fails to deliver.
In the future arc, he is shown to have learned everything about the mafia and seems to be okay with it. Though he still acts like he is still clueless most of the time.
Takeshi uses a bat that Reborn gives him. The bat turns into a katana when swung faster than 300km/h, though he initially did not have much skill in using it. He later receives a kendo blade from is father that becomes a sword when using the Shigure Souen Style.
Takeshi shows a great level of mastery with the sword and the power of the Vongola rings. Takeshi has stated that he practises with his sword every day and if even 0.01g chips off his sword he would sense it. He has a box of a swallow capable of making heavy rain and attacking opponents.
He also borrowed an attack of Squalo's called Attacco Di Squalo(Shark Attack) which when hit by his blade causes a moment of Paralysis because it is fused with his Rain Tranquility flame. It then dulls the paralyzed person's body.
The Shigure Souen Style is a notoriously deadly sword style that is only passed down to worthy successors. Each 'form' of the style is only shown once to the student - if the student is worthy to succeed, he only needs to see it once to remember how to use it from then on. However, as new forms were created the weaker branches deteriorate and others disappear as there is no worthy successor. Hence this style can be called as the perfect, flawless style.
The Shigure Souen Style taught to Yamamoto consist of 8 forms; four defensive, four offensive. Yamamoto has further created at least three new forms, forms 9, 10 and 11.
In the sky match he was revived by Hibari. Meeting up with Gokudera, the two then proceeded to the gymnasium to rescue Chrome. The second they entered the field however, they had been trapped into Marmon's illusion, after Belphegor rescued him. They were required to surrender the rings, in exchange for Chrome's life. Yamamoto devised a cunning plan to turn the tables on the two. However this backfired and they were ultimately saved by Ryohei, who broke the gym and the illusion.
Nine years and ten months into the future, Takeshi is no longer the oblivious person he used to be. He makes his first appearance when he arrives to lead Lal Mirch and the accompanying Tsuna and Gokudera to Vongola's secret hideout. As he tells Tsuna about the war, we learn that his father has been killed. His future self was replaced by the younger Takeshi later during a fight with members of the black spell.
At the beginning of Lal's training, Takeshi drew out the ring's power in an instant, however his flame was only strong enough to open one of his boxes. He fought a losing battle against Gamma with Hayato when they were searching for the future Hibari, during which he had a fight with Hayato. Both of them worked together but were beaten badly in the end. They were saved by Hibari, and Takeshi began a new intensive training with Reborn as his home tutor.
Yamamoto's training reached a point where Reborn cannot help him anymore as he is a gunman, not a swordsman. Therefore he shows Yamamoto a video that Squalo has given him roughly titled 'The Road to becoming the Swords Emperor'. It has recorded the 100 battles Squalo won for him to be declared the new Swords Emperor. This video gave Yamamoto new motivation and after three days, he is able to use his newly created Shigure Souen Style form to pierce Reborn's hat. Reborn declares his training complete. Following his training, Reborn tells Yamamoto about the secret of the Arcobaleno, but asks him not to tell anyone else until after their attack on the Millefiore base.
During the attack against the Millefiore he was he was separated from Ryohei and Gokudrea when Shouichi transformed the base. Afterwards, while following a map of the Millefiore's base Yamamoto encounters the Millefiore's strongest swordsman, Genkishi. After chargeing forwards with his Scontro Di Rodine (Clash of the Swallow) he was knocked unconscious by Genkishi's Mist Box Weapon, as since the beginning of the fight the construction of the room had been an illusion.
Wipo Publishes Patent of Nec and Takeshi Yamamoto for "Communication Device, Method for Identifying Identification Information Belonging to Communication Partner, Method for Transmitting Reply Information and Recording Medium" (Japanese Inventor)
Sep 27, 2013; GENEVA, Sept. 27 -- Publication No. WO/2013/140861 was published on Sept. 26.Title of the invention: "COMMUNICATION DEVICE,...
Wipo Publishes Patent of Nec and Takeshi Yamamoto for "Communication Device, Method for Specifying Identification Information for Communication with Communication Partner and Recording Medium" (Japanese Inventor)
Sep 30, 2013; GENEVA, Sept. 30 -- Publication No. WO/2013/140854 was published on Sept. 26.Title of the invention: "COMMUNICATION DEVICE,...
Wipo Publishes Patent of Nec and Takeshi Yamamoto for "Communication Device, Communication Method and Recording Medium" (Japanese Inventor)
Mar 01, 2013; GENEVA, March 1 -- Publication No. WO/2013/027490 was published on Feb. 28.Title of the invention: "COMMUNICATION DEVICE,...
Wipo Publishes Patent of Toyota Jidosha, Denso, Hirofumi Kanazawa and Takeshi Yamamoto for "Water Pump" (Japanese Inventors)
May 20, 2013; GENEVA, May 20 -- Publication No. WO/2013/068806 was published on May 16.Title of the invention: "WATER PUMP."Applicants: TOYOTA...
Wipo Publishes Patent of Nireco, Takeo Yamada, Shingo Kawai, Shinji Hayashi, Takahiro Yamakura and Takeshi Yamamoto for "Measuring Apparatus and Measuring Method" (Japanese Inventors)
Aug 26, 2013; GENEVA, Aug. 26 -- Publication No. WO/2013/121518 was published on Aug. 22.Title of the invention: "MEASURING APPARATUS AND...