Yasashii Akuma

Rika Furude and her group of friends live in the small mountain village of Hinamizawa; in June 1983, they welcome transfer student Keiichi Maebara into their ranks, making him the only boy in their group. After school, they have fun playing games and spending each day living their lives to the fullest. Despite this seemingly normal routine, Keiichi begins noticing strange behavior from his friends, who seem to be hiding the town's dark secrets from him. Elsewhere, a certain person watches these increasingly unsettling events unfold and remembers all the times that this, and other similar stories, have played out. Using that knowledge, this person decides to fix these broken worlds. However, when certain variables change, the individual is faced with a horrifying realization: they have no idea what to expect or how to stop the impending tragedy. [Written by MAL Rewrite]

In the not-too-distant future, the human world has long been overpopulated. Humanity marched to the stars in search of a new home, and just as this was going on, the moon's alignment caused massive earthquakes to ripple across the world, lasting several decades. Humanity was demolished. When the land finally recovered, humanity reemerged to face this strange yet familiar world. Will we, who once lorded over this domain, still remain the masters of this world? (Source: Yu Alexius Anime Portal)

Recap of all 13 episodes of Vivy: Fluorite Eye's Song.

The word cerebrum refers to a gigantic system consisting of collision universes, which is called cerebrum universe. The story starts from a series of unknown murders, unravelling the secret hiding beneath the entire universe, ranging from horrifying conspiracies to galaxy wars, from anti-human betrayals to honourable sacrifices. Having realised her weakness and backwardness, mankind takes the last stand. (Source: Official website)