Impostor (Replica).Mikoto is being stalked by Mitsuki Unabara, the Tokiwadai Middle School principal's grandson, since the last week of summer vacation. She sees Tōma and his friends passing by her dormitory and decides to pretend to go on a date with him. After an embarrassing mix-up with hotdog sandwiches, Töma learns from Mikoto that less than ten of the Sisters remained in Academy City...