Souda Kazuichi in the Despair-Inducing Causality

The events of Danganronpa 2 from Nagito Komaeda's point of view.

Hope's Peak Academy is a government-approved private high school that scouts "super high school level" students with superb talent from all over the country. But when 16 new students, including the "super high school level lucky student" Nagito Komaeda, arrive on the day of their entrance ceremony, they suddenly find themselves on a southern island called Jabberwock Island as a "school excursion" with some of their memories lost...

(Source: MAG Garden, translated)

Manga adaptation of Danganronpa 2.

Hajime Hinata, who enrolled in Hope's Peak Academy, a place where Ultimate talents gather, was excited to begin his high school life. However, he suddenly becomes dizzy and ends up on an island with 15 other "Ultimate" students... in order to escape from the island, they must kill someone and get away with it. Who kills and who gets killed? As suspicion spreads, the first murder occurs, and the Killing School Trip begins.

(Source: Amazon, translated)

Chiaki Nanami is the Ultimate Gamer, selected as one of Japan's most expert teens to attend the elite Hope's Peak High School. What could be nicer than for the semester to kick off with a class trip to the tropical resort of Jabberwock Island? And what could be more horrific than being told by the principal that now they're all trapped there, and the only way they can ever leave is to play a murder game!

The rules are simple: to escape, you must not only kill a fellow student but get away with it, as the survivors will then cross-examine each other in a class courtroom. If they vote the wrong person guilty, the killer goes free, and the rest of them die! With no margin for error and high stakes, the Ultimate Gamer will need to use all her playing skills to suss out the secrets of Jabberwock Island and find the "true ending" for Nanami and her friends…survival and escape!

(Source: Dark Horse)