Frieren And Fern In The Lewd Dungeon Official

Original anime: Frieren: Beyond Journey's End is a fantasy anime where Frieren, a demon, embarks on a journey after her fellow adventurers die. She meets Fern, an imp, who guides her. There's no character named Fern in the main cast, but maybe there's a fan-made story with that name. Alternatively, maybe the user is confusing it with another anime or a fan fiction that adds a new character, Fern, into the story.