Tsunade

is a supporting character in the anime and manga series Naruto. She took over the direction of Konohagakure after Hiruzen Sarutobi died, thus becoming the Fifth and present Hokage. Along with Orochimaru and Jiraiya, she is one of the Legendary 3 Sannin of Konoha. She excels in medical ninjutsu.

Background
Tsunade is a former student of the Third Hokage. Tsunade and her former teammates, Jiraiya and Orochimaru, are known as the or simply the "Sannin". The word is often attached to Tsunade's name because she is the granddaughter of the First Hokage and the grandniece of the Second Hokage. Tsunade is well known for her extremely large breasts (106 centimeters as stated by Jiraiya), despite the fact that Jiraiya referred to her as "flat-chested Tsunade" during their childhood.

One of Tsunade's noteworthy possessions was a crystal that belonged to her grandfather, which is said to be valuable enough to "buy three gold mines and the mountains on top of them" as stated by Jiraiya. On her brother, Nawaki's, twelfth birthday, Tsunade gave the amulet to him in the hopes that it would help him achieve his dream of becoming Hokage. The next day, Nawaki died as one of the many casualties of the war going on at the time, and the amulet was returned to Tsunade's possession. Sometime afterwards, Tsunade fell in love with a man named Dan, who also wanted to become Hokage. As a sign of her affection and in the hopes that it would help him achieve his goal, Tsunade gave him the amulet as well. Dan too would go on to die a bloody death during the course of the war, once again returning the amulet to her possession.

With the deaths of the two she loved the most, Tsunade came to lose faith in the title of Hokage, believing that only fools would want such a position. With these changes of ideals, Tsunade left Konoha with Dan's niece, Shizune, taking the latter in as her apprentice.

Personality
The deaths of Dan and Nawaki greatly changed Tsunade; Dan's death and her failed attempt to save him gave her a fear of blood, causing her to freeze upon seeing it (which very likely also impaired her summoning ability). The amulet's repeated returns to her also led her and many others to believe that it was cursed, and whoever Tsunade might give it to would die soon after.

Tsunade is also a compulsive gambler who has the unfortunate disadvantage of having terrible luck. As a result, she has been elevated to a comical status as for the gross profits others have made off her misfortune and gambling addiction. In the rare instances that Tsunade hits a winning streak, she believes it to be a bad omen, and bad things do tend to happen to her afterwards. The symbol on the back of her coat,, means "gamble", or "wager", as gambling is one of her favorite pastimes.

Tsunade typically projects a tough demeanor, even when facing great personal difficulty, and rarely compliments or praises people. She readily criticizes others for their faults, such as Naruto for his immaturity or Jiraiya for his perversion (though her habits are rarely any better). On occasion, though, Tsunade often shows sympathy for others, consoling Shikamaru that while he failed his mission to return Sasuke to Konoha, all of his teammates survived.

Tsunade has a pet pig Tonton, that is usually kept in the care of Shizune and though she doesn't speak human language she seems to understand everything and react quite actively.

Search for Tsunade arc
After his failed invasion of Konoha, Orochimaru seeks out Tsunade. Upon finding her, he asks her for a favor, though before he can specify what this favor is she declines, having already noticed his wounded arms. Trying again, Orochimaru asks her to heal his arms, explaining that the injury is a result of his carelessness when killing the Third Hokage. Shocked by this revelation, Tsunade prepares to kill Orochimaru, though he once again intervenes by offering to resurrect her dead loved ones: Dan and Nawaki. Interested in this offer, Tsunade considers it, and is left a week to decide.

Soon afterwards, Tsunade is approached by Jiraiya and Naruto Uzumaki who want her to become the next Hokage. After turning down the offer and ridiculing it, Naruto challenges Tsunade to a fight, enraged that someone could disrespect the title of Hokage due to his undying desire to become Hokage himself. Tsunade accepts and easily wins, though not before witnessing Naruto's attempt at using the Rasengan. Intrigued, Tsunade makes a bet with Naruto to master the jutsu in a week, and if he wins he will get the First Hokage's amulet. Naruto accepts, and resumes his training. As the week progresses, Tsunade keeps a careful eye on Naruto's progress and all the while contemplates Orochimaru's offer. When the week is up and Naruto appears to have failed in mastering the jutsu, Tsunade goes to meet Orochimaru, though not before drugging Jiraiya to make sure he doesn't interfere.

Upon meeting with Orochimaru, Tsunade asks that he not destroy Konoha when his arms are healed. Orochimaru complies, and Tsunade prepares to heal him, though is interrupted by Orochimaru's assistant, Kabuto Yakushi. Kabuto, being a medical ninja himself, was able to notice the killing intent of Tsunade's healing jutsu and as such knew that she really intended to kill Orochimaru. Her motives known, Tsunade reveals that she knew Orochimaru lied when saying he'd leave Konoha alone, and that she couldn't bring herself to allow it due to Nawaki and Dan having loved Konoha until the end of their days. While she had tried to forget this fact over the years, Naruto's determination and desire to be Hokage reminded her of their dreams, and she has decided to do whatever is necessary to protect those dreams.

With that, Tsunade attacks Orochimaru, though Kabuto fights her in his place. As the two trade blows, Kabuto begins to realize that he is completely outmatched and decided to use her fear of blood to his advantage by slitting his wrists and thus making her immovable. As Kabuto begins to beat on Tsunade, Shizune and Naruto come to her rescue. While both are easily defeated, Naruto is able to overcome his injuries and continue to protect Tsunade. Although Tsunade tells him to run, Naruto refuses, and manages to hit Kabuto with a perfected Rasengan in his effort to protect her, defeating Kabuto. As Naruto collapses and is left near-death due to Kabuto's last attack, Tsunade rushes to his aid and attempts to heal him, not willing to allow him to die. Her efforts are successful, and Naruto claims the amulet he has now won before losing consciousness. Putting the amulet around his neck, Tsunade asks once more for its wearer to become Hokage.

Orochimaru, worrying about what kind of threat Naruto may become when he gets older, tries to kill him, though Tsunade blocks that attack as a human shield. Orochimaru inquires as to why she is protecting Naruto, to which she replies that Naruto will someday be Hokage and that she will not allow him to die before that happens. With that, Tsunade accepts the title of that she had been offered and overcomes her fear of blood, her first action being to attack Orochimaru. Joining forces with the still drugged Jiraiya, the two attack Orochimaru, with Tsunade eventually being the one to deal the finishing blow. Defeated, Orochimaru escapes, vowing to destroy Konoha once he's healed himself. Once Naruto recovers, the group returns to Konoha, Tsunade ready to take the role Dan and Nawaki so dearly desired, and secretly believing that Naruto will someday become a great Hokage.

Sasuke Retrieval arc
Soon after arriving in Konoha, Tsunade heals the wounds of Rock Lee, Kakashi Hatake, and Sasuke Uchiha. Once healed, Sasuke defects from the village so that he can go to Orochimaru, and Tsunade is forced to send out a group of Genin to stop him. She also uses Konoha's reacquired alliance with Sunagakure to call in a favor for reinforcements, hoping to give the retrieval team some backup. Despite her efforts, the group ultimately fails, and Tsunade helps in healing their fatal injuries, bringing them back to full health. In the aftermath of Sasuke's betrayal, Sakura Haruno asks to become Tsunade's apprentice, which Tsunade gladly accepts.

Anime filler arcs
Tsunade appears in numerous filler arcs, though she typically does nothing more than sending others out on missions, occasionally trying new ways of deciding who will go on a specific mission. Her goal during the filler arcs is to keep Naruto busy until Jiraiya comes back to prevent him from going after Sasuke himself. In one filler arc, she summons Katsuyu to deal with some impersonators of Rock Lee and Might Guy who have entered the village.

Part II
After Naruto's return to Konoha after the timeskip, the village's elders question Tsunade's decision to allow Naruto to go out on missions when Akatsuki seeks to capture him. As such, the elders force Tsunade to allow one of Danzo's, a fierce opponent of the Third Hokage, men to be teamed with Naruto. Not trusting Danzo, Tsunade assigns Yamato to lead Naruto and keep an eye on Danzo's addition to the team.

Later, when two Akatsuki members enter the Land of Fire; namely Hidan and Kakuzu, Tsunade mobilizes the Niju Shotai to look for and, if possible, capture the Akatsuki duo. While capture never comes to be possible, the Akatsuki members are both defeated. Tsunade later performs an autopsy on Kakuzu, and finds Naruto's newest jutsu, Wind Release: Rasenshuriken to be too dangerous for use based on the damage done to Kakuzu's body and Naruto's arm. She explains that the attack had struck at a cellular level, causing extensive damage to the both of them, and regretfully tells Kakashi and Yamato not to allow Naruto to use the jutsu again, lest his access to chakra be destroyed.

Hunt for Uchiha arc
When Jiraiya decides to do battle with the enigmatic Pain, Tsunade bets that Jiraiya will die, but says this jokingly, due to her horrible luck in betting. Unfortunately, Jiraiya dies, possibly making this one of the few bets Tsunade ever won. Before his death Jiraiya sent a toad to Tsunade with a code which would reveal Pain's true identity. When Pa returned to Konoha with the results of the battle, he told her of Jiraiya's death. With both Jiraiya and Orochimaru dead, she is the sole surviving Sannin. After telling Naruto about Jiraiya's death Naruto quickly blames Tsunade for his death then storms off afterwards. Tsunade is then shown telling Shikamaru to have Jiraiya's message decoded and is subsequently seen crying by herself, knowing she lost a precious friend.

Invasion of Pain
Tsunade requests the return for Naruto after finding out that Konoha is under attack. However, the village elders interfere who request that Naruto is not to be alerted out of fear for him to be captured by the Akatsuki. Tsunade angrily grabs them both by the collar, and responds by telling them that they can't treat him like a child forever and that Naruto has the will of fire that enables him to protect Konoha as well as being able to surpass Jiraiya. After mentioning that others had faith in Naruto's abilities which is something they never had, just as people before them had faith in them, they must entrust this faith to the future generation, and so Koharu Utatane reluctantly gives into her demands.

Tsunade is then informed by Shizune about a Chakra receiver found in Pain's body that is used to control the other Pains through a chakra transmission and Tsunade orders Black Ops to guard Shizune and the interrogation squad to complete the investigation into Pain's identiy. Tsunade summons Katsuyu and asks her to disperse into smaller slugs and take Tsunade's chakra to heal the injured. She then vows to live up to her title of Hokage to protect the village with her life.

Abilities
Even though she is in her fifties, Tsunade's Transformation Technique makes it appear as if she were still twenty (which Naruto calls "living a lie"). Tsunade's transformation is somewhat different from a normal transformation as it seems to be permanent, not getting dispelled when she is slashed or injured, and she apparently does not need to exert any effort to stay transformed, albeit it seems to temporarily shut down when her chakra runs low, as seen when she and Jiraiya were fighting Orochimaru.

Tsunade's trademark ability is her inhuman strength, which is amplified even further with chakra control. By storing chakra and releasing it at the point of contact, she can enhance her strength to the point where she can effortlessly break through boulders with her bare hands. She is also renowned for her tremendous skill in taijutsu, which combined with her strength makes her a truly dangerous kunoichi for anyone to face directly.

In addition to her unrivaled strength, she is equally impressive and renowned for her expertise as a Medical-nin, and can heal wounds that most others would consider impossible with relative ease. Her knowledge of the medical arts are so great that she can immediatly determine what kind of injuries or illness a person has from a single glance as she did with Orochimaru when he came searching for her. The most extreme example of her medical prowess is Creation Rebirth, a technique that makes use of the massive amounts of chakra available after using Shadow Seal: Release to continuously regenerate the cells in her body, healing any wound and even growing back missing organs. It gives her a form of "immortality" in battle that even Orochimaru expressed envy for. It is because of these skills that she is regarded as Konoha's strongest kunoichi. However, because of the rapid cell regeneration, the technique shortens her life much like the Four-Tailed transformation, although she has more control over the process. Because of the risk associated with the technique, Tsunade has made the choice to only use Creation Rebirth in extremely desperate situations.

Additionally, Tsunade can summon Katsuyu, a giant slug that is intelligent and very loyal to her. Katsuyu is able to perform a number of jutsu, such as spitting acid and splitting into smaller slugs, which can recombine to form the main body once again. Tsunade can use the slugs as a medium for her medical jutsu, allowing her to heal far more people than she can individually reach.

Creation and conception
Tsunade's name is taken from the character of the same name from Jiraiya Goketsu Monogatari (自来也豪傑物語, "The Tale of the Gallant Jiraiya"). The Tsunade in that story excelled in slug magic and was married to Jiraiya. The name "Tsunade" (綱手) means "mooring rope."

Trivia

 * Her young appearance is not because of a transformation but rather her powers of bodily manipulation by frequently changing her physical appearance to look like previous ages sometimes a teenager, a mature lady, or somewhere in between those ages.
 * Tsunade has gone from being the only Hokage with a first name, to being the only Hokage without a surname.
 * Despite her age, her stamina, vitality, and physical prowess still seems to be quite high. It is likely that her immense knowledge as a medical expert has allowed her to maintain youthful-like health.
 * Her surname aperently isn't Senju because even after her grandfathers name was revealed she still as Tsunade and not Tsunade Senju in the latest databook.

Quotes

 * "One of the Legendary Sannin taking on a snotty nosed Genin...I oughta be ashamed of myself."
 * "This is the Big One...where I bet it all...where I put my life on the line."
 * "I may not be anyone's idea of perfect, but I am Hokage now...and even though I shouldn't dirty my hands on a little squirt like you...one finger's all I need."