High school student ShÅtarÅ Tatewaki heads out of town with the eccentric osteologist Sakurako KujÅ, who promises to buy him shrimp from the village. While digging around for bones, ShÅtarÅ ends up uncovering a human skull with a bashed-in frontal bone with an almost entirely intact Sphenoid bone. Against Sakurako's wishes, he calls the police, though she uses circumstantial evidence to prove that the skull is actually from around a century old. As the policeman escorts the two to the station, he lets slip a "lovers" double-suicide that also happened in the same village, and Sakurako begs him to let her see the bodies. While the local detective is quick to pronounce the cause of death as a lovers' suicide, Sakurako points out that the knot tied around the wrists and the lack of fluid inside the bodies prove that it was a homicide someone wanted to disguise as a suicide by the ocean. Despite her hard work, ShÅtarÅ catches Sakurako trying to sneak the original skull out of the police station, and makes her leave it on the way back home.