Told from the viewpoint of the father Morio, "A Boy Called H" follows a young boy named Hajime Senoh, nicknamed "H". His father, Morio runs a tailor shop. With the onset of World War II, their family must endure difficult times. Nevertheless, H is filled with curiosity and a sense of justice. Based on the autobiographical novel "Shonen H" by Kappa Senoh (published by Kodansha, July 9, 1999).

The fairy tale follows a young man named Gusukō in the Tōhoku forests of northeastern Japan in the 1920s. After an onslaught of droughts and natural disasters, Gusukō is forced to leave his home and search for a better life elsewhere. Gusukō joins a group of scientists at the Ihatov Volcano Department, which deals with the same natural disasters that drove Gusukō from his home.

In 1969, Kenji, an elementary school kid and his friends built a secret base during their summer holidays. They fantasized that they had to fight villains who were out to conquer the world and wrote them in the Book of Prophecies. Years later in 1997, Kenji becomes a convenience store manager and leads a regular life after giving up his dreams to become a rock star. His boring life is suddenly turned upside down when his old classmate dies mysteriously and an entire family in the neighbourhood disappears. At the same time, a religious cult and its mysterious leader, Friend emerges and a strange chain of events duplicating exactly the events described in the Book of Prophecies follow. Is this the beginning of the end of the world? Who is Friend?