Keiko Takemiya
In 1970, Hagio befriended Norie Masuyama and manga artist Keiko Takemiya. Masuyama is credited with introducing Hagio and Takemiya to literature, music, and films that would come to heavily influence their manga: "Demian", "Beneath the Wheel", and "Narcissus and Goldmund" by Herman Hesse, as well as other novels in the "Bildungsroman" genre recommended by Masuyama, came to influence Hagio generally and "The Heart of Thomas" specifically. Hagio has stated that Hesse's works "opened up one by one the dams that had stopped up the water [...] I heard a voice saying 'yes, you can write. Yes, you can express yourself the way you like. Yes, you can exist.'" That same year, Hagio and Takemiya watched the 1964 Jean Delannoy film "Les amitiés particulières", which depicts a tragic romance between two boys in a French boarding school. The film inspired Takemiya to create "In the Sunroom", while Hagio began to create "The Heart of Thomas" as a personal project that she did not expect would ever be published.