One Piece is currently in the climax of its Wano Country arc, which began nearly four years ago and has, since then, become the longest-running arc in the series. Although Wano is quite long when compared to most arcs in the story, it is also pivotal to the overarching plot, being Luffy's biggest step forward towards attaining the One Piece itself. In Wano, Luffy is going head-to-head against one of the Yonko of the Sea in Kaido in an attempt to defeat him and liberate Wano Country.