The Japanese writer Mori Mari (森茉莉; 1903‒1987) is considered the spoilt “daddy’s girl” of literary luminary Mori Ōgai and a precursor of the Boys’ Love/yaoi-genre. She also had a reputation for being unconventional – a character trait that was expressed in her fictional and non-fictional works. Mori Mari authored a number of autobiographically inspired texts in which she staged several literary alter egos that were met with keen interest by the public. The novel Amai mitsu no heya (The Room of Sweet Honey) portrays its protagonist Moira as a narcissistic shōjo (young girl) in a symbiotic relationship with her father, while a series of essayistic novels describe the everyday life of the headstrong Mure Maria, a famous character of humoristic literature in Japan. The novel Kioku no shomotsu (The Book of Memory), on the other hand, is reminiscent of a Japanese shishōsetsu, a first-person novel in its account of Mari’s failed first marriage. The study by Anne Dastig-Balland deepens our understanding of Mari’s personality, life course, and literature by examining biographical material, Mari’s non-fictional self-portrayals, and the characterization of her autobiographically inspired protagonists in the light of psychoanalyst Karen Horney’s theory of personality. It provides an extensive presentation of Mari’s biography and illustrates its arguments with numerous original translations of excerpts from her whole oeuvre. For her contemporaries, Mori Mari was an eccentric, but also an astute observer of society. She was ahead of her time with regard to social issues such as gender and the environment, which may explain her enduring popularity.