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).

Teru has been brought up in a hill town and spent his childhood conquering the slopes on his bicycle. Being a cycling fanatic, who resents defeat, he joins Kamegaoka High School, which used to boast a powerful cycling club. There he meets Hatomura, an ace of the club who wants to turn around he club which has deteriorated to the point of dissolution, and Yuta, an aloof cycling genius with unshaken confidence in his speed who does not allow others to follow him. Meeting a rival that is faster than him for the first time, Teru joins the club in order to challenge them. His only interest, however, is his own cycling speed. Joining the club teaches Teru the importance of teamwork to support the lead cyclist and to place priority on the victory of the team.

Shuji Mimura works as a broadcast writer. He learns that he doesn't have much time left to live. He decides to concentrate on the future of his beloved family. Shuji Mimura's final plan is to find the best man to marry his wife Ayako.