Kei Enomoto (Satoshi Ono) works for a Tokyo based security company. By the request of attorney Junko Aoto (Erika Toda)'s, Kei Enomoto goes to the scene of a locked-room incident with Junko Aoto's senior attorney Gou Serizawa (Koichi Sato). The locked-room case involves the death of Ooishi, the president of a funeral company. Ooishi's body was found in a locked room of a mountain villa. The police concluded that his death was by suicide, due to his room being locked and the fact that Ooishi was suffering from terminal cancer. However, Ooishi's friend Maruyama and notary Kusakabe (Keisuke Horibe) doubt that his death was by suicide and asked Gou Serizawa to investigate. Now, Kusakabe takes Kei Enomoto and Gou Serizawa to the mountain villa and explains what transpired the day Ooishi's body was found.