You used to live in a different world, accompanied by your best friend "Mori", a huge beast who was very fond of you, but by chance that life came to an end.

You were reincarnated into an ordinary student in the modern world, who is already in his last year to enter university. You are transferred to a new school and you begin your new year of classes, until a girl named Shin Kuromi takes an interest in you, and begins to follow you and look at you as if she were angry with you for something. But it turns out that that girl is "Mori" your friend who was also reincarnated into a human, who will try to do anything to make you remember her.