Leaving the events of Dressrosa behind for the Mugiwara who stayed on the island, they, along with Law and the samurai of Wa Zo, reach a land born on the back of a giant elephant: Zunisha. Among the truths about Kin'emon's journey and about the mink, mink of the island, begins the Saga of the Emperors, the ninth of the series ONE PIECE.
THE Mugiwara thus manages to join Zoand those who were not present at Dressrosa recount that they managed to escape an attack by one of Big Mom's ships. Only two of the Empress' pirates, Pekoms and Bege, arrive in Zo to capture her sanji. A kidnapping explained by basic information about the origin of the cook. In fact, Sanji is part of the Vinsmoke family and is intends to marry one of Big Mom's daughters, Pudding.
Though initially opposed, Sanji decides to accept to protect his teammates. Zo proves crucial the appearance of the first Road Poignee grips, red, and which, along with three other indicators, show Raftel's location. In front of the gigantic stone, the alliance between the Mugiwara, the pirates of Heart, the Mink and the samurai of Wano is formed Kill Emperor Kaido.
Determined to have Sanji back in the crew, however, Luffy decides to head to Whole Cake Island first, followed by Nami, Brook, Chopper, Carrot, and Pedro, who split with the others who head to Wano instead. Once in Totto Land, Luffy's group splits up to confront the Empress' children and search for his Poignee Griffe. Details about the history of the Vinsmoke family surface, as do all of those Sanji's brothers are genetically modified humans to become more powerful while remaining the only normal thanks to his mother's sacrifice.
Luffy grabs Sanji, only to be initially knocked back and even attacked. The cook worries that Big Mom might threaten Zeff and his companions. However, Sanji discovers what Pudding actually wants Kill the Vinsmoke family to give the Empress control of the technology of the Kingdom of Germany. Sanji then reunites with Luffy to blow up the wedding and deal with the aftermath.
After Brook manages to find the details of three Poignee handles, Jinbe intends to abandon the crew of the Empress, and Capone and Caesar Clown try to stop them, the Mugiwaras are back in action. After attempting a plan that turns out to be flawed, Big Mom goes into a state of uncontrolled anger because he wants to eat the now destroyed wedding cake. So begins a race against time, with Sanji trying to bake a cake that can satisfy the Empress's hunger on the one hand, and Luffy competing against Katakuri on the other in the mirror world.
there first part of the emperor saga, told from chapter 802 to 902, It ends with Luffy's victory and the escape of the Mugiwaras, including Sanji, from an angry Big Mom, foiled by the Sun Pirates and members of Germa 66.