This engaging series of childhood recollections tells of an unconventional school in Tokyo during World War II that combined learning with fun, freedom, and love. The school had old railroad cars for classrooms and was run by an extraordinary man – its founder and headmaster, Sōsaku Kobayashi – who deeply valued children's independence, and who was a firm believer in freedom of expression and activity.
The suspense story begins when Jin Saeki, a policeman in Yamanashi Prefecture, arrives at a prominent estate residence in response to a tip, and finds the skeletal remains of 13 children, as well as a mysterious marking. Jūzō Haikawa, the long-missing owner of the estate, immediately becomes the prime suspect. Saeki collaborates with a woman named Kanon Hasumi, who has a connection to Haikawa, and together they search for the truth behind the case. In a parallel story set in Tokyo seven years after the case, a girl with a connection to the mark left on the Haikawa estate runs away from home.
