The Actress Blogger's Locked Room Case (Part 1)

While at a cake buffet with Genta, Mitsuhiko, Ayumi, Haibara, and Professor Agasa, Conan and company meet Kitami Saya and Shono Kyona, two actresses who hate each other. One threatens to expose the other if they aren't careful. Not long after, Kyona was found in her hotel room dead, but the room was completely locked.