That filename corresponds to a based on the Magical Girl Lyrical Nanoha series, focusing on the popular NanoFate pairing (Nanoha Takamachi × Fate Testarossa Harlaown). The work is by MercurianAngel Satashi , a known creator in the Nanoha fandom, and it’s labeled yuri (female-female romance), English , and adult (indicating mature content).
It looks like you’re referencing a specific fan work file: That filename corresponds to a based on the