is one piece episode 637 filler?

In the participant's viewing area, Don Chinjao tells Luffy and Cavendish about Garp's reputation in the past, and how he is considered a demon by many pirates, and about how Garp gave him scars. Cavendish questions Luffy about his true identity, but Luffy tells him that he isn't Luffy, and is Lucy.

Chinjao states that he will take out his grudge from Garp on Luffy, and Luffy replies by telling Chinajo to take it out on Garp instead. Cavendish then asks Luffy if he is really Garp's grandson, and Luffy replies by saying that he is Lucy.