After sailing the harsh seas of the world of One Piece, the bonds between the Straw Hat Pirates are now almost unbreakable. They know almost everything about each other, and they are willing to sacrifice even their own lives if it means helping their crew mates. Each of them also has a dream ambitious enough to make most people laugh. Even so, none of them think of their dreams as absurd, especially when it comes to Luffy becoming the Pirate King. However, despite their seemingly unbreakable bonds, there were also moments that tested their friendships — and the first one to betray their pirate crew was none other than their navigator, the Cat Burglar Nami.
Source：https://www.cbr.com/one-piece-why-nami-betrayed-straw-hat-pirates/
