Ino Yamanaka

is a secondary character in Naruto who is on Team 10 with Choji Akimichi and Shikamaru Nara, under the leadership of Asuma Sarutobi.

Background
Ino has known Sakura since the two were very young, and was a considerably more popular and self-confident girl than her at the time they met. She convinced Sakura that hiding the size of her forehead was pointless, and gave her a ribbon to draw attention elsewhere, suggesting that Sakura had great potential, but had yet to reach it. When Sakura became attracted to Sasuke, and found out that Ino was attracted to him as well, Sakura ended their friendship so they could properly compete for his affection. Ino later made friends with Sakura again during the Chunin exam, but they are still considered rivals by many, including Asuma.

Personality
Ino is somewhat superficial, constantly thinking about boys and hoping by dieting to lose weight will make her be more attractive to them. Ino can also be very confident, and outspoken, and isn't afraid to speak her mind and sometimes suggests that Choji should lose weight, but in the filler arcs, she explains that his fat is essential for his techniques. She is attracted to Sasuke, but her reasons for that attraction, apart from Sasuke being a popular student and the best in his class, are unknown (not unlike Sakura's attraction to Sasuke).

In her team, Ino tends to boss the others around. Shikamaru, despite thinking of most girls as "troublesome," typically offers no resistance, being unwilling to deal with how she reacts if she is unable to have her way. Asuma recognizes the control she has over the others, and while dying, tells her to look after Choji and Shikamaru and ensure that they do not get into trouble and don't let Sakura surpass her.

Despite her superficial bossy persona, Ino has a soft side to her, and is capable of being compassionate at times. She develops a strong bond with her teammates which grows greatly when the trio are faced with the loss of their teacher.

Ino has shown to possess a good level of intelligence, in the Konoha 11 filler arc, she was able to figure out that the Academy is the location of where Genno planted the explosive, sharp enough to figure out that Asuma was seeing Kurenai, has the uncanny ability to be able to tell a person's occupation by the condition of their hands, and manages to learn medical ninjutsu which is no easy feat.

Chunin Exams
In the anime, Ino played a small role in Episode 3, being upset when she did not get onto Sasuke's team while Sakura did, and being dismayed to be on the same team as Shikamaru and Choji.

Ino later reappeared in the Chunin Exam. She used her Mind into Body (or mind transfer) technique to enter Sakura's mind and memorize all her test answers, then sent her mind into Choji and Shikamaru's minds to give them the answers. In the Forest of Death, she helped Sakura and Rock Lee fight off the Sound Genin until Sasuke, his Cursed Seal having awoken, forced the Sound Genin to retreat.

Ino's first match in the Chunin Exams was against Sakura. The two did not battle seriously at first, until Sakura, unwilling to have Ino pity her, denounced her. Ino and Sakura battled seriously afterward and used up most of their energy in the process. Ino then attempted to enter Sakura's mind after cutting her hair and sending chakra into it to immobilize her. She succeeded, but was expelled by Inner Sakura (after encouragement from Naruto). Low on chakra, Ino and Sakura charged at each other for one last attack, and knocked each other out, resulting in both of them being eliminated. When they regained consciousness, they started becoming friends again, but still maintained their rivalry over Sasuke.

Ino accompanied Sakura to visit Sasuke in the month between the preliminaries and the finals, but found that he was gone. She went to the finals with Sakura, and noted that Sakura's team was extraordinary after seeing Naruto defeat Neji. When the invasion started, she was rendered unconscious by Kabuto's genjutsu; Sakura briefly considered waking her to help pursue Sasuke, but Kakashi told her that a group of more than four people (herself, Naruto, Shikamaru, and Pakkun) would not move effectively.

Filler arcs
In the filler arcs, Ino accompanied Naruto, Shino and Anko to the Land of the Sea, and helped defeat Misumi Tsurugi by possessing him and tying his arms to pillars, leaving him trapped in a collapsing room. Ino then used Mind-Body Break (or Mind Destruction) Technique on Yoroi as he attempted to attack Shino, allowing Shino to punch Yoroi away. When Yoroi attempted to attack Ino, Shino sends his bugs after him, defeating him.

She later appeared in a mission with Naruto, in which she tried to replace a princess who has grown overweight in an attempt to woo her suitor. Ino was barely able to stand the man, but the mission succeeded after Naruto, while interfering, accidentally exposed the real princess, during this Ino briefly revealed an "Inner Ino" similar to Sakura's "Inner Sakura".

In the Konoha 11 arc, Ino and Sakura were sent to examine a corpse that was believed to be that of Genno. Ino hesitated, but eventually entered the room, and concluded from the condition of the hands that the corpse was not a ninja or a carpenter, and that Genno was still alive. After the group found Genno, she attempted to possess him when he tried to make his escape on a summoned bird; while he let go of the bird, Ino was unable to maintain the technique, as she noted that he had been suffering terrible pain the entire time. Genno died shortly after his plans were foiled, possibly from what had caused that pain.

In the Shitenshounin arc, Ino accompanied Shikamaru to help rescue Temari. Her attempt at possessing their opponent Kyaku failed, leaving her at risk. Kyaku later was defeated by Shikamaru and Temari's combined efforts. Feeling guilty that she did not contribute much to the mission, she asked Sakura to ask Tsunade to add her as a second apprentice. Sakura agreed, but added that she would be Ino's senior apprentice (leading to yet another fight).

Sasuke and Sai arc
Ino made her first reappearance shortly after Team Kakashi and Team Guy returned from the successful saving of Gaara, with her hair grown long again and sporting a more revealing attire. She appeared shortly after Sai attacked Naruto along with Shikamaru and Choji to test Naruto's skill level. After the failed attempt to retrieve Sasuke, Ino appeared again with Team Asuma to visit Kakashi in the hospital. While oblivious of what happened, she was pleased to see Naruto again and cheerfully said hello.

After Team Yamato returns from its failed attempt to retrieve Sasuke, Ino appeared again with Team Asuma to visit Kakashi in the hospital. Quickly, she became infatuated with Sai, noted that his looks and attitude reminded her of Sasuke. Later while eating a meal with Team Kakashi, minus its captain, Ino attempted to get close to Sai with some casual flirting. Sai, attempting to make friends with his new acquaintances, tried to use what he learned from his books by kindly calling Ino "Beautiful". This resulted in Ino blushing madly and Sakura going into a fit of rage from Sai treating her poorer by calling her "Ugly".

Fire Temple Filler arc
When word of villages on the border of the Fire Country had been attacked, Ino, along with the rest of Team Asuma, went to investigate. Later, during the attack on Konoha, Ino did her part in the resistance by performing her duties as a medical ninja. As Naruto tried to calm Sora, he talked about his friends and the Kyuubi. It was assumed that the Konoha 11 knew about him being the container of the Kyuubi.

Hidan and Kakuzu arc
When Tsunade decided to make a move against the Akatsuki, Ino was assigned along with Choji, to a Niju Shotai team lead by Aoba Yamashiro and Raido Namiashi. Ino and Choji arrived as backup for Shikamaru and Asuma in their fight with Akatsuki members Hidan and Kakuzu.

As the Akatsuki pair left due to being called back by Pain, Ino tried to use medical ninjutsu to heal Asuma's injuries, though she knew that there was nothing she could do to save her sensei. Asuma, also knowing that he wouldn't make it, gave some parting words to his team. To Ino, Asuma said that her spirit was strong and that she was a helpful child, so she should take care of Choji and Shikamaru. Asuma also told Ino not to lose to Sakura in ninjutsu or in love, to which Ino agreed. After smoking one last cigarette, Asuma died.

Shikamaru, Ino, and Choji all agreed to avenge Asuma. Under the guidance of Kakashi, Team 10 later set out to face Kakuzu and Hidan. By using her Mind Body Switch Technique on a hawk, Ino was quickly able to find the Akatsuki duo so Shikamaru's plan could begin. During Team 10's fight with Hidan and Kakuzu, Ino played the role of an observer, her Mind Body Switch Technique being too much of a risk to use in battle. The anime though expanded on Ino's role. As Choji was about to be killed by Kakuzu, Ino threw a shuriken which proved enough to distract Kakuzu so Shikamaru could attack. She was quickly grabbed by Kakuzu and nearly had the life choked out of her, until Shikamaru saved both her and Choji. She later healed Naruto after he defeated Kakuzu.

Pain's Invasion
When Pain began his invasion, she along with Choji, Kiba, Shino, and Hinata saw the devestation. She then ran into the interrogation chamber to warn her father. Later, she along with Shizune, her father, and Ibiki were attacked by Animal Path Pain with Human Path at the interrogation chamber. Shizune, Inoichi, and Ino left Pain's bodies to Ibiki so that they could figure out the truth about Pain with Inoichi's new information. Ino, her father, and Shizune then moved to the code deciphering office.

Abilities
Ino is considered one of the more talented kunoichi in the academy, shown by how she excelled in kunoichi infiltration training. She is fairly skilled in most ninja arts. She primarily uses mind-affecting jutsu, such as the Mind Body Switch Technique, a jutsu used for reconnaissance also a jutsu that is a coming of age jutsu for the Yamanaka clan, which allows her to possess someone and control that person's actions for about two to three minutes. However, her body feels any pain that the target feels while possessed, and she will die if the target dies. Missing results in her being unconscious for several minutes while her mind returns to her body, leaving her extremely vulnerable. The anime takes her skills a bit further by giving her the Mind Body Disturbance Technique, which causes the person effected to lose control of their body. As long as Ino can hold the hand seal and the amount of chakra she has is how long the technique lasts. By Part II, Ino has become a Chunin and medical ninja. Ino has been considered rather capable in medical ninjutsu. During Pain's invasion, her father communicates to Ino using telepathy. This skill may be a part of Ino's arsenal of abilities. Back when they were younger, Sakura and Ino were compared often in ninja skills, and while Ino is fierce, Sakura proved to be the better ninja of the two, which only drives Ino to become better for herself and for Asuma. While Ino has not had much on-screen battling, in several games, Ino is shown to be have great taijutsu prowess from her powerful kick combos with, setups, aerial combos and powerful drill kick combos. Also in some games, she is known to use a purple flower called Ninja Wolfsbane which generally poisons her targets and other moves related to flowers. And in newer games she has shown to have skill for genjutsu.

Trivia

 * Fans have speculated that Deidara was related to Ino because of their close resemblance.
 * Ino and Hinata are among the characters who have the least amount of plot time and demonstration of their skills and abilities.
 * Ino's mother has never been seen or heard.
 * While stated as taller than Sakura, in most appearances, Sakura is usually the one that is taller.
 * Before the final anime-exclusive filler arc before Shippuden, the reason for Ino's decision to become a medical-ninja was unexplained.