Natsuki Tono

Natsuki receives limited direct characterization because most information about her comes from events remembered eight years later. She was close enough to her older sister Mizuki Tono that the accident involving her profoundly shaped Mizuki's subsequent life.

The film focuses more heavily on the circumstances surrounding Natsuki than on her everyday personality. It therefore does not establish detailed interests, ambitions or personal abilities for her.

Natsuki is an ordinary human with no established combat abilities, supernatural powers or professional specialization.

Her importance to the story does not derive from a particular skill. Instead, the circumstances surrounding the incident involving her become one of the central mysteries connecting Kitanosawa's past to the new crimes occurring eight years later.

Natsuki is introduced through the history shared by Mizuki Tono, Keisuke Yamao, Fuyumi Tachihara, Takehiko Muto and Shogo Hikawa. Eight years earlier, she was involved in a traffic incident on the road to Kitanosawa.

The accepted account holds that Yamao struck Natsuki while driving and subsequently served a prison sentence. The incident is followed the next day by Touma Tachihara's mysterious fall, which leaves the young boy unconscious for years.

Touma's recovered memories eventually reveal that the accepted version of the accident is incomplete. Mizuki had pushed Natsuki during an argument, sending her into the roadway immediately before Yamao's approaching car struck her.

The same night is connected to Yamao's much larger secret: he was returning from a jewelry-store robbery with stolen gems. Touma witnessed evidence of the crime, leading Yamao to pursue him before the boy fell from a cliff. Natsuki's accident therefore becomes the point where several hidden events from eight years earlier intersect.

Mizuki Tono is Natsuki's older sister. [Although Mizuki initially allows Keisuke Yamao to bear responsibility for the accident, Touma's recovered memories reveal that Mizuki Tono accidentally pushed Natsuki into the road during an argument. The guilt remains central to Mizuki's actions eight years later.](#spoiler)

Keisuke Yamao was driving the vehicle that struck Natsuki. He served a prison sentence for the hit-and-run, making the incident the publicly understood reason for his long absence from Kitanosawa.

Touma Tachihara witnessed crucial events surrounding Natsuki's accident. [His memories eventually reveal both Mizuki Tono's role in Natsuki entering the road and Keisuke Yamao's connection to another crime committed that night.](#spoiler)