It was originally coined by science fiction and fantasy writer Jacek Dukaj, for his 2004 book Perfect Imperfection.
From the surname of the author, this, and similar neopronouns created by him, are referred to as dukaizmy, and after a term coined by him, also known as the "post-gender pronouns" (Polish: zaimki postpłciowe).
[1][2][3][4] While "ono" is a neuter Polish pronoun typically used for animals and objects, indicating inanimacy, "onu" serves as a more specific option for non-binary people,[5] which varies among individuals, with some opting for male, female, or neutral pronouns depending on the context and their personal preferences.
[6] It's also about adaptation of language to accommodate non-binary identities,[7] where "onu" is part of a set of pronouns that may be used to refer to individuals who do not identify strictly as male or female.
[6] This is part of a broader discussion on how Polish, being a heavily gendered language, presents challenges for non-binary speakers who seek to express their identities without conforming to traditional masculine or feminine forms.