One day, Chizuru (Nana Asakawa) and Mioto (Aino Kuribayashi) enters problem-solving office Kurogarasu. The two girls look naive, but Chizuru is a leader of a enjo kosai group. Their group makes money by having young girls date older men for money. Thugs are threatening Chizuru for money. Chizuru pays 2.5 million yen to the problem-solving office Kurogarasu for their help. Kuroto (Tsubasa Sakiyama), Yuya (Keisuke Ueda) and Hina (Moga Mogami) take the case and begin to investigate the thugs, but they find something unexpected.