Meet Misaki, a 14-year-old schoolgirl who has recently moved from Tokyo City to her deceased grandfather's house on Hohoro Lake. Although she spent little time there as a child, she is now experiencing flashbacks of playing in her grandfather's lab while he conducted experiments. On a walk home with her friend Sanae, Misaki was pelted with small toys resembling the Loch Ness monster, which Sanae explained was a local legend called Hohopo. While searching for the culprit, Misaki slipped down the hill and discovered the real-life version of Hohopo staring at her from the lake.