Totonou Kuno (Masaki Suda) goes to visit the grave of Yoshikazu Miyoshi (Asami Mizukawa). Then, there was Haruo Tenda (Kosuke Suzuki), and he thanked him for remembering the anniversary of the death of Kiwa, who was once a partner of Tenda. Tenda invites his high school classmates and guests to a mystery party at the villa and asks them to come. Also, I talked about the arrival of Seiko Furo (Sari Ito) at my lecture, and I heard from Furo that Sei was cooperating with the police, so I showed off mystery solving skills at the mystery meeting. I want you to do it. When Sei is having trouble answering, Tenda reassures him that he is just a part-time job to help carry luggage and clean up meals. And he added that he had only one request.On the promised morning, when Sei went to the meeting place, Tenda came to pick me up by car. I was surprised to see the bath light in the car. She told her that she invited her because Furo Hikaru was enthusiastic about her studies, and she told them not to tell the people who gathered at her meeting that she was a detective.Tenda's car running in the snow arrives at a mountain lodge covered with ivy. According to Tenda, it is called 'Ivy House'. It was Takakatsu Tachibana (Kuranosuke Sasaki) who welcomed the heavens and the men at the entrance. In addition, the owner, Kaoruhei Tsuta (Mansaku Ikeuchi) was waiting in the mountain cottage. Tenda, Takashi Tachibana, and Tsuta are high school classmates. Tsuta has also invited Della (Hiromasa Taguchi) and Pan (Kento Shibuya) to be guests of the Mystery Society.After allocating rooms, the mystery party starts at night. Tsuta began to talk about her death as the former owner of the villa fell off the balcony.