Assassination Time

Class 3-E waits tensely as their impossibly fast homeroom teacher touches down and strolls in for roll call. On cue from Nagisa Shiota, the students open fire, but the creature slips past every pellet and calmly takes attendance, then chides them that leaning on sheer numbers over individual thought will never work against his top speed of Mach 20. To prove the point, he blasts off one of his own tentacles, showing that the government-made anti-sensei BBs wound him while leaving humans unharmed, before regenerating seconds later and forbidding any shooting outside genuine assassination attempts.

As an English lesson proceeds, Kayano nods toward the crescent moon and Nagisa drifts into memory. He recalls how the moon was suddenly reduced to a permanent sliver, and how the same creature appeared in their classroom announcing Earth would follow next March. A Ministry of Defense agent, Tadaomi Karasuma, then laid out the top-secret assignment: kill the monster. The creature, insisting he was born on Earth, had struck a bargain to teach Class 3-E instead of being hunted, which let the government track him daily and gave thirty students close-range chances to strike, all backed by a ten-billion-yen reward. A demonstration followed, the creature trimming Karasuma's eyebrows mid-dodge to display his speed.

Over lunch the teacher zips off to China for mapo tofu, and the class marvels that their assassination target is also a genuinely gifted educator. Ryoma Terasaka pulls Nagisa into a scheme, handing him a toy grenade packed with gunpowder and three hundred anti-sensei rounds. During fifth period, as the tired teacher's face flushes light pink, Nagisa approaches with a concealed knife, lunges, and clamps onto the creature so Terasaka can trigger the blast. The teacher survives by having shed his skin that month, using the cast-off membrane to shield Nagisa from harm.

Enraged, his face turned pitch black, the creature races across town and returns with the students' house nameplates, warning that while he cannot hurt them, their families were never part of the deal. Yet his fury dissolves into praise: he commends Nagisa's natural technique and scolds the others for failing to protect their classmate, urging the class to see themselves as worthy of their target. A brief memory shows a dying woman in a ruined building begging him to teach these children. He then declares he fully intends to destroy the Earth and dares Nagisa to stop him. Smiling, Nagisa promises to kill him first, and Kayano christens their unkillable instructor Korosensei.

Class 3-E is revealed to be under the instruction of the creature who destroyed most of the moon and threatens Earth within a year. Karasuma briefs the class on the government's secret assassination contract and its ten-billion-yen reward. The teacher demonstrates that anti-sensei weapons harm only him by severing and regenerating a tentacle. Terasaka and Nagisa attempt a grenade-based assassination, which the teacher survives using his shed skin to protect Nagisa. Nagisa vows to be the one to kill him, and Kayano coins the name Korosensei.

This first episode of the Assassination Classroom anime adapts the opening manga chapter, also titled Assassination Time, and premiered in Japan on January 9, 2015. Its themes are the opening Seishun Satsubatsuron and the ending Hello, shooting-star. The adaptation makes several changes from the manga, such as removing the students' protective eyewear, reassigning certain lines of dialogue among characters, expanding Nagisa's narration about the moon with additional worldwide newscasts, and altering the poem's required closing phrase to end with the words about being tentacles all along.