Content Warning: Both the source material and this guide contain depictions of graphic physical violence and war-related deaths, the death of a child, sexual assault, rape, domestic abuse, suicidal ideation, suicide, miscarriage, and references to infanticide.

In the mountain village of Takayubi in the Shirojima Province of the Kaigenese Empire, 14-year-old Mamoru climbs the mountains to his high school, Kumono Academy. He encounters another boy who introduces himself as Kwang Chul-hee, a transfer student from a distant northern region of Kaigen. Together, they climb the rest of the way. Chul-hee comments on the traditionalist aesthetic of the school, which looks like something out of “one of those old samurai movies” (8). He explains that his father Tae-min works for a communications company and is there to lay cable so that the mountain village will have access to modern technology.

Misaki, Mamoru’s mother, sits at home with her two youngest sons: two-year-old Nagasa and infant Izumo. Her other son, five-year-old Hiroshi, attends an elementary dojo. Misaki’s sister-in-law, Setsuko, and friend, Yukino Hyori, keep her company with their own children: Setsuko’s daughter Ayumi, and Hyori’s son Ryota. Setsuko and Hyori are jealous of Misaki’s four strong sons, but Misaki says she would be happy with daughters.