Part of: 亡刻のシェオル (Series) favorite_border

[DeepL Translation - needs review] Introduction to Volume 1: Three boys and a girl wake up in an enclosed space with no calendar. They are given archive data on humans who once achieved time navigation, and a curriculum to prepare them for their "mission" that will begin in 400 days. Will they be able to find a future where humanity can survive?

(Translator: DeepL)