Aoba, who lives a pretty ordinary life, works at the junk shop "Mediocrity." The manager asks him to make a delivery one day, but he finds out that there's nothing at the address he was supposed to deliver it to. It was then that Aoba was consumed by light and he was within a mysterious world.
But then, what exactly is a heart?
لكن ما معنى "القلب" بالتحديد؟
Aber was bedeutet es dann,
 ein Herz zu besitzen?
Pero entonces... ¿qué es el corazón?
Pero entonces... ¿qué es el corazón?
Mais…
Mas, nesse caso, 
o que exatamente é o coração?