Memento Game

Memento Game summary:

Shinonome Yuuya, a failure at the prestigious Yuunagi Academy.
Hitsugi Akari, the top student of the year, is also a loner like him.
Despite being opposites in many ways, they share a certain similarity.
Suddenly, the two of them fall deep into the underground of the academy and get caught up in the games of the hidden world beneath Yuunagi Academy, Yomosugara Academy!!
In a school where an eternal night reigns, the games are played in pairs, and the rewards are the mysteries of this world and their own past memories!!
Will they be able to uncover the truth of this world—?
A survival game school suspense where “memory” and “trust” are the key!
(Source: Comic Walker, edited)