Sunny was a very quiet boy, after he accidentally killed his older sister, he never left the house again and just slept in his bed, constantly dreaming with the "Dreamworld", a world where MARI, his older sister, is alive.

However, he constantly saw someone else with him and his friends in the dreamworld, but he never saw that person.

One day, when he finally decided to leave home, he notices his friend, KEL, had a New friend, and this friend was the person he used to see in the dreamworld.