In 2017, thirteen skeletal remains of children were discovered in the basement of a mansion, with a mysterious hexagonal mark on the wall. Detective Jin Saeki and his team investigate the identities of the victims and the whereabouts of the mansion's owner, Juzo Haikawa. Kanon Hasumi, who calls Haikawa "father" despite no blood or legal ties, reveals that she was rescued by him and lived with 19 other children in the mansion. She insists Haikawa is not the culprit. Fast forward to 2024, a young girl goes missing in a bustling district. Reporter Toko Mori visits Saeki, who is no longer a detective, and questions whether the case is truly closed. (Source: Japanese = YTV || Translation = MyDramaList)