Mizuki (Naruto)

"You think a runt like you could beat me?! You're welcome to try little fox!"

- Mizuki taunting Naruto.

Mizuki is a villain from the Naruto manga and anime. He was an evil ninja who betrayed the Leaf Village and attempted to steal a secret scroll from Naruto's possession in order to give it to Orochimaru.

Past
Mizuki was the best friend of Iruka Umino in his youth, but soon began to grow jealous of him following the attack of the Nine-Tailed Fox. Iruka's parents had died in the attack, and Mizuki noticed that Iruka was getting more attention from the villagers. Despite his newfound hatred towards Iruka, Mizuki still pretended to be his best friend, while at the same time relishing in his misery. When Mizuki applied for a teaching position at the academy, the Third Hokage discovered that one of Mizuki's teammates had died of suffocation on a mission, yet had only a minor, non-lethal leg wound. Mizuki was turned down and Iruka instead got the job, causing him to eventually hate the Leaf Village.

As it turns out, Orochimaru himself saw Mizuki murder his teammate, which piqued his interest. He left him with instructions for a potion after giving him a Curse Mark.

Betrayal
After Naruto was the only one not to graduate with the rest of his classmates, Mizuki manipulated him into stealing the Scroll of Seals to improve his skills. He originally planned to kill Naruto and take the scroll for himself, but soon after, Iruka showed up and revealed Naruto's identity as the Nine-Tailed Fox. After hearing Iruka defend him, Naruto helps him fend off Mizuki, using the Multiple Shadow Clone Jutsu that he learned from the scroll. After Mizuki was beaten into unconsciousness, he was declared a missing-nin and incarcerated in Konoha's maximum security prison.

Escaping from Prison
In the anime-exclusive Mizuki Strikes Back arc, it is revealed that he actually intended to give the Scroll of Seals to Orochimaru. He planned to escape from prison with the help of the Legendary Stupid Brothers and create the potion that Orochimaru requested. After his escape, he was bent on getting revenge on both Naruto and Iruka. His former lover, Tsubaki, remarked how he used to be kind before he began following Orochimaru, and tried to get him to abandon his quest for vengeance. He would not listen, however, and knocked her unconscious.

After dueling with Iruka and nearly killing him with paper bombs, Mizuki broke into the Nara laboratory to get the ingredients and fled to cave where he could concoct his potion. The potion activated his curse mark, causing him to increase in strength and speed as well as transform into a tiger-like humanoid. Realizing they can't win in a fair match, Iruka guides Naruto away from the battlefield, which prompts Mizuki to give chase. Unfortunately for him, Mizuki is led into a field of sealing paper bombs, paralyzing him so that Naruto could hit him with his rasengan. The effects of the potion destroyed his cellular structure and left him in a condition where he could never return to the life of a ninja.

After his defeat, Tsunade interrogated him on the whereabouts of Orochimaru and Sasuke, but he gave no useful information, as he was not aware that Orochimaru's base in the Hidden Sound Village had been destroyed. After being healed and saved by Tsunade he returned to prison where he presumably spent rest of his life.

Appearance
Mizuki has white shoulder-length hair with a slight hint of blue to it and green eyes. He wore the standard attire of the Konoha-nin before his defection, which included flak jacket and forehead protector that he wore like a bandanna.

Upon being sentenced to the Konoha Strict Correctional Facility, he wore the prisoner's uniform of a gray tunic with matching pants, with his prisoner number on the back, and going barefoot. During this time, he became much more muscular and well defined in build to the point Naruto didn't recognize him at first. When Mizuki escaped from prison, he changed into an opened black vest, tight black pants, and a dark brown belt which had a silver rectangular belt buckle.

When Mizuki drank the potion concocted from his cursed seal, he gained tiger-like stripes, which also gave him much more feral look. After the potion's effect wore off and his cells began a self-destruction, Mizuki shriveled up into a frail and decrepit old man, his skin darkened brown and his skin heavily wrinkled. However, Tsunade managed stabilized his deterioration, and even restored his appearance to his original form, before his time in prison.

Personality
Originally, Mizuki appeared to be very polite and kind-hearted, and was described to be a sweet man by his former fiancée, Tsubaki. In reality, he doesn't care for anything or anyone beyond his own rise in power. He takes pride in the fact that he is not bound by things like morals or teamwork, and is very willing to sacrifice whatever he has to in order to complete his goals. His desire for power seems to come from what appears to be an inferiority complex, as he can't stand having anyone look down on him. Although Tsubaki claimed that Mizuki was a sweet man before meeting Orochimaru, even that was a facade as he already showcased his underhanded and ruthless methods since childhood, having a manipulated friendship with Iruka for his own benefits, and later murdering a comrade who suffered a minor injury, justifying his actions by claiming he is merely eliminating any potential hindrances for the mission's smooth success. Mizuki's defining characteristics are being greatly ambitious and dishonorable.

Mizuki's craving for power and acknowledgement led him to hate Iruka for gaining more attention than him, and pretended to be Iruka's friend in order to live off of that attention, as well as discreetly inflict misery on Iruka. Because of this, during their second confrontation, Mizuki constantly mocked Iruka while refusing to surrender and repent no matter how many times Iruka tried to convince him to. Due to his disregard for comradeship and friendship, Mizuki detests the Will of Fire, insulting it when Iruka tried to encourage Mizuki to look back into it, dismissing it as irritating nonsense. In what is perhaps an attempt to make him even more of an antithesis to Naruto, Mizuki's least favorite food is ramen, which happens to be Naruto's favorite. Mizuki also has a particular hatred for Naruto, seeing him only as the Nine-Tailed Demon Fox. His avarice even drove him to ignore Tsubaki's love, having no more feelings for her himself, as he took advantage of her lingering affections for him and used her to benefit himself, and then attacking her when she begged him to stop, even physically tossing her aside later on. Upon discovering that Naruto gained acknowledgement after risking his life to defend the village, Mizuki grew angrier than ever at him, refusing to accept the boy's heroism, and instead accused the villagers of being too excited.

When Mizuki overheard the Third Hokage and the examination committee suspecting his field of conduct as a reason for not promoting him, he felt that they wronged him for accomplishing a mission at all cost, and developed strong grudge against the village for feeling they neither appreciate nor understand his powers and efforts. He reached his tipping point of betraying the village when Orochimaru praised his actions and gave him a cursed seal; Mizuki came to the conclusion that Orochimaru truly acknowledged his potential, and hold the renegade to high regard. Mizuki believed if he went to Orochimaru, he would be granted even more power, and attempted to steal the Scroll of Seals as a means to please him.

Trivia

 * Mizuki's name means "cornel", a variety of the dogwood shrub.
 * His dislike of ramen is very likely a metaphor for his hatred towards both Naruto and Iruka.