Yuta Hibiki wakes up in the home of his classmate, Rikka Takarada, with amnesia. A voice from an old computer, identifying himself as "Gridman," has a mission for him, but can he even survive the next day of school without his memories?
Ah, the boy from yesterday.
Ach, der Junge von gestern.
Ah, el muchacho de ayer. ¿Cómo estás?
¿Aún tienes pérdida de memoria?
Le petit amnésique !
Ah, o menino de ontem.
Como está? Se lembra de algo?