While Sasaki Rena is out, Abiru Yoshinori arrives at the Suma Research Company. When Suma Yasuomi and Minemori Kotoha go to meet him, he informs them that he met Rena the previous day. Furthermore, he gives them a small box tied with a ribbon and asks them to give it to Rena. Suspecting a listening device may be planted inside the box, Kotoha decides to check at the suggestion of the Detective Department's Doi Shuzo.