The plot begins when Shoutarou Tatewaki, a high school student and assistant to the eccentric osteologist Sakurako Kujō, discovers a young girl named (nicknamed "Li-cha") wandering alone at night.
: This episode is noted for shifting the series into a darker, more procedural tone, often compared to Western police procedurals rather than traditional anime tropes. The plot begins when Shoutarou Tatewaki, a high
: Yuuka has blood on her bag and an improperly treated injury on her arm. Shoutarou brings her to the police, but they are unable to identify or contact her parents. Shoutarou brings her to the police, but they
: Shoutarou contacts Sakurako for help. Upon meeting Yuuka, Sakurako manages to calm the child down by eccentrically ranting about the beauty of bones. : Inside the house, Sakurako discovers a hidden
: Inside the house, Sakurako discovers a hidden compartment in the floor containing a second child—Yuuka's baby brother—who is near death from heatstroke. While Sakurako performs life-saving measures on the infant, a drug-crazed murderer (the children's father) returns and attacks the police officer outside before entering the home.
: Using Yuuka’s belongings and specific clues from her injuries, Sakurako leads the group to a gruesome crime scene—a house where the children’s mother has been murdered.