Duke is a character from the anime There Was a Cute Girl in the Hero's Party, So I Tried Confessing to Her. He is depicted as a former subordinate of the protagonist, Yōki. Duke belongs to the dullahan species.

In the narrative, Duke serves as a side character who is part of the group of monster guards that are friends with the protagonist. His role within the story is notable but secondary; he is described as a nice character who primarily appears to assist Yōki when he is needed. No specific information is available regarding Duke's background before becoming Yōki's subordinate, his personal motivations, or his personality traits. Similarly, there are no details on his key relationships with other characters beyond his association with Yōki, nor is there information on any character development he may undergo throughout the series. While his species is identified as a dullahan, no notable abilities or powers specific to his character have been documented.