Vision Time

Korosensei leads the class in swimsuits to a pool he has built deep in the forest, and everyone dives in until a splash and a rocked chair reveal a fresh weakness: their teacher cannot swim. Terasaka alone stays apart, convinced the class is growing to like Korosensei rather than kill him, and even his friends Muramatsu and Yoshida are warming to the octopus. After he smashes a model motorbike and sets off a smoke can in disgust, Karma coldly challenges him to kill Korosensei himself if he hates him so much.

Alone by the pool, Terasaka is approached by Shiro and Itona, who pay him to carry out a plan and needle him about having no vision, forever a weakling next to someone like Karma.

Terasaka fires a gun Shiro gave him as a supposed signal, but it detonates the dam, and the surge sweeps the class toward the cliff, forcing Korosensei to save them at reduced speed thanks to the laced water and the earlier smoke. Karma punches the stunned Terasaka back to his senses, and when Itona ambushes the weakened octopus, Terasaka warns that Hara is also in danger on a failing branch. Karma has Terasaka take Itona's tentacle strike, and the smoke still clinging to his unwashed shirt makes Itona sneeze and falter.

Muramatsu and Yoshida leap in to splash Itona, the rest of the class follows, and with every advantage gone Shiro concedes and withdraws with Itona. Terasaka becomes a true ally, though Nagisa notes an even graver weakness of Korosensei's went unnoticed that day.

The episode adapts Chapters 43 and 46 through 49. Natsuhiko Koyama appears in a flashback. It first aired in Japan on April 24, 2015.