Aki Fujino

Aki is a young girl who commits suicide at the start of the story by jumping from the top of a building. During the investigation, it is discovered that she had been writing a novel and corresponding with Mizorogi, whom he'd met at a party hosted by his publisher. She has a twin sister named Sakura, whom she's been separated from since they were young, when their parents divorced; however, the two had reconnected shortly before Aki's death.