Twintailed Attack on the Brother and Sister

Nao briefly spots a twin-tailed girl, similar to what appeared in Shūsuke's photo album. At school that day, a girl named Iroha Tsuchiura joins Nao's class and makes friends with Nao. Iroha later comes to Shūsuke, reintroducing herself as his childhood friend and kisses him, proclaiming they are lovers due to games of Doctor they played when they were young. Shūsuke feels ashamed of his past perversion, throwing away all his porn and his perverted nature, which causes Nao to grow concerned. Meanwhile, Shūsuke becomes increasingly worried that Iroha seems to know everything about his private life, and later she blackmails him with threats of telling Nao about their games of Doctor.