Detective Anzai was called to the site of a hotel under construction in the Hakoda region, where the skeletons of twelve children were discovered. She was surprised when Detective Yamazaki showed up, convinced that the skeletons were of twelve children that had disappeared in Matsuda twelve years earlier.

However, Anzai is skeptical in the older detective's assessment... and even more so when Yamazaki dragged Misaki Saiki in to help him.

(source: Absolute Anime)