A sudden rumor starts spreading throughout the school: A monster named the Human Snake was found in an abandoned reservoir.
The protagonist, the Boy, who wanted to investigate what was going on, went to the reservoir looking for an adventure. Eventually he meets the monster, and they start to develop a unique relationship.
How will their relationship impact the Boy? What exactly is the body of the Human Snake? Unexplainable incidents start to happen around the school campus. All of the incidents are interrelated between the Boy and the monster. What is the truth beneath it all?