Kazuki works as a rookie host at a club. One of his regular customers is Mai, but she disappears. Mai has a tab of 6 million yen with the host club. The bar owner orders Kazuki to find Mai within a week or Kazuki will have to pay back her debt. Kazuki turns to problem-solving office Kurogarasu. There, Kuroto, Yuya and Hina are hired by Kazuki to find Mai.