The blue monster is a failed living battle weapon created by an exiled mage. For his selfish needs, the mage took care of the monster without a spare of warm affection.

He forces dozens of monster scraps to the monster each day to make the monster stronger causing the monster to be hideous and disgusting that can no longer maintain a human form. However, the monster remains weak and useless leaving the mage to abandon the monster completely.

The blue monster has to learn to survive in this dog eat dog world, until one day, a child appears in the Forest of Monster: Perrin Egloff

It's not easy for a seven-year-old child to survive in this poisonous forest.

10 years later, the child matures to adulthood and meet the monster once again.

A monster who had come to care for the child, and the child who had come to care for the monster.

Their story began once again.