Kido Tsumiki

is an Anbu executive from Konohagakure, formerly a high-ranking member of Root.

Background
Kido was raised by his father and mother, the former of whom dedicated all of his income to send Kido to the Academy, so that he could have a higher chance at a better life. However, when his father began faking taking his medicine to save money for Kido's schooling, he eventually succumbed to his sickness. Because of this, Kido grew an addiction to money. In time, Kido became a powerful and skilled shinobi like his father dreamed him to be, strong enough to attract the attention of Danzō Shimura, who placed him in Root. Over time, Kido became the organisation's treasurer and was even rumoured to have financed, laundered and monitored all of Danzō's finances for his unsanctioned operations. With Root's disbandment upon its leader's death, Kido became an Anbu executive.

At some point in time, Kido and his subordinates collected hair samples from Sasuke Uchiha and had his aid, Magire, create a chakra-enhancing medicine in hopes of creating an artificial way to bestow a person with the Sharingan. After the Fourth Shinobi World War, Konohagakure began considering to lower military-related budgets in favour of other projects, causing Kido a great deal of worry. Desperate for continued income, Kido began orchestrating small security incidents, involving high officials in the village, to ensure continued funding.

Personality
Kido's poverty-related childhood problems made him a miserly, money-obsessed individual, whose mind was constantly thinking of wealth, forcing him to make poor decisions in his life. Because of this obsession, Kido was not above using his position as an Anbu to cause trouble in the village, such as attacking the Fire Daimyō and Homura Mitokado, a member of the Konoha Council, to ensure that the budget for Anbu would never be depleted even in the slightest. Even when the current Hokage, Kakashi Hatake, and others quickly realised he was the mastermind behind many security related events, Kido refused to stop his plans, showing a dedicated and stubborn side of his character that compromised his ability to make the correct and wise choice when necessary.

Kido's obsession with money stemmed unto his perception of others as well. He had a low opinion of Sakura Haruno and Ino Yamanaka's "Children's Mental Healthcare Clinic" because they treated children mainly with low cost but highly effective therapy instead of just giving children prescriptions for medicine, which would bring in far more revenue but questionable results. Because of this, medical professionals like Shizune had a very low opinion of Kido.

Abilities
Being an Anbu executive and a high-ranking member of Root before the former's disbandment, Kido is undoubtedly a very powerful shinobi.

Chakra
Kido is a powerful shinobi who also possesses a strong amount of chakra. This is best seen when Kido took in the Tailed Beast Drug, and generated a full cloak of nine-tails; the amount of tails created by a user of the drug is dependent on the amount of chakra they possess. This chakra is shown to be hard, and different from the shrouds that other users of the drug wear; it causes Kido to resemble a purple humanoid, and it can withstand even a chakra-enhanced punch from Sakura Haruno, cracking and peeling away but regenerating quickly. More astonishing, this cloak had given Kido the power to generate Black and White Chakra, and thus create powerful Tailed Beast Balls, able to perfectly balance the 8:2 ratio required to form the technique. While nowhere near as powerful as that of a true Jinchūriki or Tailed Beast, Kido's Tailed Beast Balls provide him a significant amount of firepower above that of most ninja.

Juinjutsu
Kido is capable of putting a cursed seal on his allies, in a similar fashion as to how Danzō used his Cursed Tongue Eradication Seal, as a way to protect his secrets from leaking. The seal was designed to cause its wearer to explode if they divulge sensitive information.

Taijutsu
Kido has shown himself a practitioner of taijutsu, entering combat with Sakura Haruno, herself a specialist, before even ingesting the Tailed Beast Drug. His body itself is honed and muscular, indications of practice in physical arts.

Kenjutsu
Being an Anbu, Kido uses and is apparently skilled in close-range swordsmanship.

Intelligence
Kido proved himself to be scientifically intelligent, as he, along with the medical-nin Magire, were able to synthesise drugs that allow one to mimic the genetic traits of a Tailed Beast cloak and Sharingan. He was also cunning, causing minor disturbances to ensure funding, though his greed has blinded him from the investigation closing onto him, leading to his downfall.

Sakura Hiden: Thoughts of Love, Riding Upon a Spring Breeze
Fearing a decrease in Anbu's budget was inevitable during the peace time, Kido orchestrated a couple minor security incidents with Konoha VIPs, such as the Fire Daimyō and Homura Mitokado, to ensure continued funding over the "Children's Mental Healthcare Clinic" despite the results it was producing. Before leaving, he voiced his disapproval over the clinic, earning him a glare from Shizune.

Later, upon realising his incidents were being investigated by Kakashi, Kido began sending his subordinates to kill Kakashi's agent Sai. Understanding that the three he sent were killed without succeeding, Kido knew it was only a matter of time before he was discovered and urged Magire to complete their shared project before it was too late. However, as he realised Sasuke was ignoring him, and needing fresher material for his experiments, Kido sought to find another way to force Sasuke to return by ordering his associates to capture Sakura (but not to kill her, yet) hoping her "relationship" with Sasuke would force Sasuke to return if she were endangered.

After drugging Sakura into unconsciousness, tying her up and bringing her to one of his hideouts, Kido and Sakura engage in a conversation; Kido admits to kidnapping her so Sasuke will return to the village and, once he succeeds in capturing Sasuke, he hopes killing Sakura will cause Sasuke's Sharingan to get stronger and give Kido the opportunity to take his eyes. Kido further elaborates he is using drugs to create his own Sharingan and tailed beast cloaks. To prove a point to her, Kido uses one of the drugs to create an imitated Sasuke and confess his love to her, but Sakura is unimpressed.

When Kido steps away, Sakura escapes from her bounds and they fight. Kido nearly overpowers her with his tailed beast cloaks but Sakura never gives up and succeeds in defeating him and render him unable to move. Kido and Magire are taken back to Konoha, where they are interrogated by Ibiki Morino and Kido confesses that he collected hair and blood samples from Naruto to create the tailed beast cloaks. While his tragic childhood also came up as his motive for his crimes, it did not excuse his actions. It is never revealed what happened to Kido after his interrogation, but based on the severity of his crimes, it is assumed he was sent to prison.

Trivia

 * Kido's family name,, means "building blocks", while his first name has several meanings when written with different kanji:
 * When written as 木戸, it means "wooden door".
 * When written as 輝度, it means "brightness".
 * When written as 喜怒, it means "joy and anger".
 * When written as 希土, it means "rare earth".