With the opening theme "Beautiful days" by Arashi and the insert song "Orion" by Mika Nakashima, the drama series began on 17 October 2008.

The case remained unsolved due to lack of evidence and witnesses; only Taisuke has barely seen a suspect, and a plastic umbrella with no print was apparently left by the killer.

The siblings conclude that Masayuki killed their parents and stole their family recipe of hayashi rice, but they can only find circumstantial evidence.

With Yukinari's help, Kōichi and Taisuke visit the Togami residence disguised as police officers investigating the Ariake murder, and inform Masayuki that his DNA is found on an item at the crime scene, making him an official suspect.

Masayuki accidentally reveals that he is aware that the item at the crime scene refers to a plastic umbrella, causing Yukinari, Kōichi and Taisuke to believe that he is indeed the killer.

However, Masayuki reveals that he was at the crime scene that evening to purchase the hayashi rice recipe from the Ariake couple, only to find they were already dead.