In Oshiri Tantei: SHIRIARTY, a string of perplexing crimes is linked to the notorious Shiriarty, a villain determined to snatch the enigmatic treasure called the 'O-PARTS'. Butt Detective and his trusty assistant, Brown, team up with Audrey, a sleuth from the global police agency Wanterpol, to safeguard the world from the malevolent plans of Shiriarty and ensure that the 'O-PARTS' do not bring chaos and darkness upon the world.