DOCUMENT 1

APPEARANCE

In his current form, Koro-Sensei has the appearance of an alien-esque octopus (or similar mollusk). He stands at approximately 3 meters tall and has a large, bulbous head with two small, beady eyes and an enormous mouth (usually seen in his trademark grin). Koro-Sensei has several prehensile tentacles extending from his body; two of the larger ones are used for arms– each with two fingers– while the remainder are plump and used for walking. He wears a black academic dress, a small square cap with a yellow tassel, and a black tie emblazened with a yellow crescent moon emblem. Koro-Sensei's face changes colors with his mood, as follows:

Yellow/Green = Happy, EmotionlessYellow with Green Stripes = MockeryOrange with a Red Circle = Correct AnswerPurple with a Dark Purple X = Incorrect AnswerPink = SleepyPurple = Shock/PanicBlue = SadnessRed = AngerBlack = Extreme Anger

Two years in the past, while Koro-Sensei was still human, he was a lean, dark-haired man of indeterminate ethnicity.

DOCUMENT 2

POWER AND ABILITIES

Speed: Koro-Sensei's most prominent trait is his outrageous speed, which defies the limits of normal Earth organisms. It is repeatedly stated that his maximum (and most frequently used) speed is Mach 20 (20 times the speed of sound or 6,805.8 meters/second). Using this speed, Koro-Sensei can quickly travel almost anywhere in the world at any time, and easily outrun any would-be captors. In addition, in doses this speed can be used to whip up tornados and even create semisolid after-image clones. Most often, when Koro-Sensei can outspeed his foes, he prefers to annoy them by performing "maintenance" on their bodies as they attack him, all while rendering these attacks moot.Flight: Using his speed, Koro-Sensei can somehow fly at supersonic speeds, apparently without damaging or deconstituting his gelatinous body. He can even take human passengers with him and use his body to protect them from the dangers of the high speeds he moves at, though this does put him at a risk of being attacked mid-flight.Tentacles: Koro-Sensei has several prehensile tentacles about his body, which are his main limbs and the source of all his attacks and mobility. These tentacles are very strong and multipurpose, and can be formed into drills, extended over long distances, and inflict general damage. He rarely, if ever uses them for offensive purposes, due to his agreement with the Japanese Government,Intelligence: While Koro-Sensei does not have superhuman intelligence, he is one of the most intelligent characters in his own universe, and is versed in virtually all manner of topics. This is what has made him successful in his role as a teacher, both in instructing the students (in chapter 124 of the manga, it is explicitly stated that he has memorized every student workbook in Japan, all in preparation for his classes).Molting Ability: Once each month, Koro-Sensei can shed a layer of his gelatinous "skin" to evade damage or remove superficial injuries. These shed skins are nearly as invincible as Koro-Sensei himself, being bulletproof, shock-proof, explosion-resistant and elastic– making them ideal for protecting humans who lack Koro-Sensei's resistant qualities.Crystal Transformation: As an absolute last resort, Koro-Sensei can energize and compress his entire body into a minute form, consisting of a smaller version of his trademark face in an orange color encased within a thick, transparent crystal ball. In this form, Koro-Sensei is completely immune to all damage, from Anti-Sensei materials to nuclear weaponry. However, he is, at the same time, completely immobile in this form– which lasts for exactly 24 hours after initiation. Koro-Sensei has remarked that an easy way to dispose of him would be to force him into this form and use a rocket to carry him to some distant part of the universe (though the technology to do this does not exist yet in his world). Crystal Blast: Using a smaller version of his cystalline transformation, Koro-Sensei can compress a small portion of his body into energy and fire it from his tentacles, creating a powerful, albiet controlled blast of energy. This blast is strong enough to break other tentacles made of the same material as Koro-Sensei, as well as shatter solid concrete.Mucous: At any time, Koro-Sensei can emit a sticky, viscous mucous from his skin and nostrils. This mucous is primarily used to improve Koro-Sensei's aerodynamics, letting him fly in relative silence. The mucous has several unique properties in and of itself; on its own it can quickly harden and become a relatively durable material. The mucous is also shown to be water-soluable, and can form a bubbly, gelatinous solid when mixed with water. This property allows Koro-Sensei limited protection against water, making it gel before it can soak into his body. Though Koro-Sensei can create an enormous amount of mucous normally, his reserve is not infinite and can be drained through exposure to certain pesticides within a day.Damage-Resistant Body: Koro-Sensei's artificial body has a bizzare chemical composition, which can dissolve most metals. As a consequence, most conventional weaponry has no effect on Koro-Sensei, including all forms of guns, grenades, and metal blades (Koro-Sensei is even seen in one instance eating a metal knife as a method of disposal). In addition, he has described his viscous body as being similar to modern bulletproof vests, possibly rendering it immune to similar concussive or piercing blows.

FORMER ABILITIES

Charisma: As a human assassin, Koro-Sensei was infamous for his charisma, which enabled him to perform most of his jobs. It was rumored that Koro-Sensei's charm was so great it was almost akin to brainwashing, exemplified when he was almost able to convince one of the scientists holding him captive to let him go through polite conversation alone.Miscellaneous Assassination Skills: As a human, Koro-Sensei was considered a master assassin, and can be considered to be proficient in related disciplines. While none have been shown specifically yet, he has been shown using knifework and riflery, and appears to have been a skilled marksman and infiltrators.

DOCUMENT 3

​​​​​WEAKNESSES

Koro-Sensei's powers make him a nearly impossible target to challenge in combat, and have made his assassination a major problem for the leaders of the world's nations. However, he has many critical weaknesses his enemies can take advantage of to defeat him. The most critical of this is the existence of a nondescript "Anti-Sensei Material" which is completely lethal to him. The substance is harmless to humans and appears to be similar to rubber, but can be cut, powderized, dissolved, and molded into just about any shape while retaining its lethality to Koro-Sensei. Also, due to his agreement with the Japanese Government in exchange for teaching class 3-E, Korosensei cannot harm a student or allow his students to come to harm, which has made it difficult for him to show his true offensive prowess. Over the course of the series, Koro-Sensei's students keep a running record of Koro-Sensei's other weaknessess, most of which relate to his shallow personality and the other chemical oddities of his body– as listed below.

When he tries to act cool, his weaknesses show.He is surprisingly quick to panic.He is petty.His punches are weak (later revealed he has a lack of physical strength in general).Boobs.He is humble and subservient to his supervisors.He has no patience of wire puzzles.He gets motion sickness.He can't sleep on a pillow other than his own.He worries about apperances.He can't handle hot food.Getting wet (his body absorbs water and becomes sluggish).Juicy gossip.Hackneyed plot developments make him cry.He gets taken in by rumors.Time right after molding.Time right after regeneration.His body goes rigid when bathed in a special beam of light.When he returns to normal after a serious situation, he gets embarrassed.He can only draw simple pictures.Heat fatigue.He's strict about poolside manner.He can't swim (when fully immersed in water, Koro-Sensei becomes so bloated he is rendered immobile).He likes to gossip.He is weak against the occult.If he can't gather people he feels worthless.Tone-deafness.He sucks at hiding.Gets carried away by official positions.Heart (Koro-Sensei has a "core" underneath his moon-emblazened necktie– to which his tentacles are anchored– which, if damaged, can cause his death).Not related, but acts like a doting parent.Gets insurance to avoid getting hurt.He doesn't really know what "your own football" means.He sucks at reporting.He suffers from road rage.Grabbing all his tentacles at once makes him unable to move.He is easily scared of the suWeaknesses.