Koro-sensei

Koro-sensei is the main anti-hero and homeroom teacher of Class 3-E in the anime and manga series Assassination Classroom. He is a bizarre, incredibly powerful entity who threatens to destroy the Earth unless his students can successfully assassinate him before graduation.

Despite his terrifying power and the bounty on his head, he is a dedicated, deeply caring, and highly effective educator.

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Appearance

Koro-sensei has one of the most recognizable and unconventional designs in anime:

• Species/Form: He is a large, bipedal, tentacled being who closely resembles a yellow octopus.
• Head: He has a massive, perfectly bulbous, bulb-shaped head with a permanent, wide, toothy grin and small, beady black eyes.
• Limbs: He has numerous tentacles that he uses for walking, grabbing objects, and moving at incredible speeds. He usually keeps two main tentacles wrapped together to look like hands.
• Attire: He is almost always dressed like a traditional academic professor, wearing a black academic gown, a square mortarboard cap with a yellow tassel, and a large black tie with a yellow crescent moon emblem on it.

Color-Changing Face

One of his most distinct physical traits is that his skin changes color depending on his mood, emotions, or the situation:

• Yellow: His standard, relaxed color.
• Yellow with Green Stripes: Feeling cocky, smug, or mischievous.
• Orange with a Red Circle (◯): Right answer / Correct (usually when grading papers or praise).
• Dark Purple with a Black X (✕): Wrong answer / Incorrect or disapproving.
• Bright Red: Angry or enraged.
• Black: Pure, blinding fury (his face turns pitch black with glowing eyes).
• Pink: Feeling flirtatious, embarrassed, or sleepy.
• Light Blue: Sadness or sorrow.

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General Powers & Abilities

While you didn't ask for his history, his "general gist" is defined entirely by his mind-boggling physical stats:

• Mach 20 Speed: His most famous attribute. He can move, react, and fly at speeds up to Mach 20 (about $15,345\text{ mph}$ or $24,696\text{ km/h}$). He uses this speed to dodge bullets, clean the classroom in seconds, travel to foreign countries for lunch during a quick break, and even create speed-induced "afterimages" of himself to tutor multiple students individually at the same time.
• Regeneration: If a tentacle is severed, he can rapidly regrow it, though doing so temporarily drains his energy and slows him down slightly.
• Molt/Shedding Skin: Once a month, he can shed his outer skin. He can use this discarded skin as a protective shield to save himself or others from a massive explosion.
• Absolute Defense Form: When pushed into a corner, he can shrink his entire body down into a tiny, indestructible gem-like sphere. He surrounds this sphere with an impenetrable energy barrier for 24 hours. The downside is that he cannot move while in this state.
• Weaknesses: He is completely immune to standard human weapons (lead bullets and steel knives just melt inside him). He can only be harmed by a special material called "Anti-Sensei BBs" (rubber-like pellets) and specially designed plastic knives. He also has hilarious personal weaknesses, like getting motion sick easily, being afraid of water, and having a massive sweet tooth.

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Personality & Role

• The Ultimate Teacher: Despite the global threat he poses, Koro-sensei genuinely loves his students. He looks at the outcast kids of Class 3-E and treats them with absolute respect, building up their confidence, figuring out their individual strengths, and helping them excel academically and personally.
• Playful and Goofy: He is often incredibly childish. He loves reading gossip magazines, eating expensive sweets, and getting teased by his students.
• Protective: If anyone outside the classroom tries to hurt his students, Koro-sensei instantly drops his goofy demeanor and becomes a terrifying force of nature to protect them.