Unable to view porn from the internet using the PC their father won at a raffle, Ako and Riko decides to buy erotic games in Akihabara. But Keita ends up accompanying them, so they devise a way to hide their real purpose for going to Akihabara. Ako distracts Keita by taking him to a cosplay shop while Riko investigates the adult section of a game shop. While changing, they run into Ako's teacher, Yūzuki Kiryū, who is a closet otaku (dressed as Mahoro from Mahoromatic Maiden). Riko later encounters her while trying to get a special edition game. After meeting Keita and being reminded about Ako and Riko's crush on him, Yūzuki drags him off to talk to him, inadvertently taking him to a cosplay-themed love hotel. After being found by Ako and Riko, the group encounter Keita's kōhai, and Yūzuki's younger sister, Mikazuki, who covers for Yūzuki by stating she was buying the game for her. In return for bailing her out, she gets Yūzuki to cosplay as Mai Shiranui for her that night.