In Episode 20, the team reaches the Old I Watergate, a Class S haunted location also known as the "Red Watergate."

The episode revolves around a mysterious boy who recounts his tragic story through drawings in a sketchbook. The boy's father is killed during a family dispute, and his mother disposes of the corpse together with another man in a gruesome manner. The neglected and abused boy is forced to live on the balcony and is eventually killed by his mother.

The team, especially Keitaro, is drawn into the boy's story and experiences vivid and disturbing hallucinations. The boy's ghost, fueled by rage and grief, attempts to express his anger indiscriminately. The episode reveals that the boy is not seeking understanding or compassion but rather a way to vent his uncontrollable fury and pain.

As the team grapples with the boy's story, they encounter a powerful spirit that takes the form of the boy's mother. This spirit threatens to harm others, driven by the same anger that consumed the boy.