The protagonist of the story is "I", named Meijia. When I was five years old, I saw a little boy with a strange hairstyle break into the house. I thought it was the Cauliflower Monster. Because only I could see him, no one believed what "I" said. Two bored children played together for a summer vacation, and gradually developed a dependent friendship from bullying each other.
That summer was the summer of blue waves that only belonged to "me".