Ep 7. E 7

Shoutarou finally convinces Sakurako to let him help with her investigations, and they head to the local library to research the bones they found in the previous episode. From what they discover, the bones appear to belong to a young girl who went missing many years ago.

Sakurako decides to visit the old factory where the girl was last seen, hoping to find more clues. They discover an old and rundown building, and upon entering, they find evidence of someone having been there recently. They also discover some old machinery and a staircase leading down to an underground area.

As they explore the underground area, they find a room that appears to have been used as a makeshift shrine. The walls are adorned with pictures of the missing girl, and there are offerings of food and other items scattered around the room. They also find a diary belonging to the girl's mother, who had been searching for her daughter for years.

Using the information in the diary, they are able to piece together the girl's last days and discover that she was abducted and held captive in the factory. They also find evidence that suggests the perpetrator is still active and may have taken other victims.

Sakurako and Shoutarou decide to set a trap for the perpetrator, using themselves as bait. They wait in the factory until nightfall, and sure enough, the perpetrator appears. Sakurako is able to use her knowledge of anatomy to subdue the perpetrator, and the police arrive soon after to take him into custody.

With the perpetrator caught, Sakurako and Shoutarou are able to bring closure to the missing girl's mother, who had been searching for her daughter for years. The episode ends with Sakurako and Shoutarou reflecting on the case and their newfound partnership, with Sakurako admitting that she may need Shoutarou's help more than she initially thought.