Think Outside the Box Time

Only Karma and Gakushu have the time and stamina to attempt the last question. Gakushu skims the closing line and reaches for elaborate formulas, while Karma, reflecting on how each classmate hides an unexpected gift, spots a key clue buried in the opening and answers with a single simple equation. He scores a flawless twenty; Gakushu lands seventeen, running out of time one line short.

The following day Korosensei unveils the rankings, and the class realizes it has monopolized every one of the top fifty places, with Terasaka landing forty sixth and Karma overtaking Gakushu for first. Karma credits a year of socializing with the outcasts for the insight that won him the final problem, while Nakamura notes that cramming cannot match bloodlust nurtured over months.

Beaten and enlightened, Class A asks to transfer to the mountain class, recognizing that its methods work. When Gakushu tells his father the students have given their verdict, the chairman backhands him, betraying a raw fatherly reaction his son has never seen. At the hillside building, every student is now free to return to the main campus, yet all choose to stay and finish their assassination.

A bulldozer then tears into the classroom with Chairman Asano behind it, announcing the board will demolish the site and move the students into prison like quarters. He produces Korosensei's dismissal papers and proposes a lethal wager: to keep his post, Korosensei must solve one problem in each of four workbooks rigged with anti sensei grenades, a challenge stacked at roughly a one in five chance of survival. The teacher takes a direct blast on the first book yet endures, pressing on toward the rest.

The gamble ties back to the pair's first meeting, when Asano ambushed Korosensei with a one second problem, and the chairman intends to fund nationwide branches of his philosophy using the money extorted from the Ministry of Defense until the teacher dies. In the manga the rigged grenades lack the S.A.A.U.S.O. acronym the anime attaches to them.