Shangri-La, an amusement park named after an ideal world In a paradise overflowing with smiles, a banquet in the name of judgment begins. A few months have passed since the nightmare of the previous work, "The Kairoukan Murder Case." Running out of material, Ikuo visits his friend, Kibukawa. When he returns to the office for the first time in a while, he is approached by Haruna Kikukawa, a beautiful secretary working at the much talked about amusement park, "Shangri-La." The request is to provide security and investigate the cult-like threatening letters and creepy pranks that have been sent to the amusement park. However, the president, Hiroshi Kimijima, asks that the matter be handled confidentially and without telling the police. Though harboring doubts, Ikuo and Izuna decide to head to "Shangri-La." An invitation from paradise brought by the beautiful secretary. A banquet called "judgment" begins from there. Are the cheers echoing through the amusement park, named after a utopia, shouts of joy? Or...?