When first published in Japan in 1997, A Boy Called H quickly became a best-seller. Over two million copies were sold, and critics hailed the book as an outstanding example of literature about World War II, although there was also a feeling that the book was not absolutely reliable in its historical details. Most of these details were minor. For example, in an incident that takes place in the book in the summer of 1942, H's sister sings a patriotic song that was not published until 1945.

When the book was translated into English and published in the United States in 1999, the critical response was enthusiastic. For Steven I. Levine, in Library Journal, the book provided "an accessible, unforgettable, and intimate introduction to the effects of the war upon Japanese family life, friendships, school, and society." Levine argued that the book belonged "with a handful of classics about children...