One piece. Vol. 6, The oath

Enhanced descriptions from Syndetics:

Join Monkey D. Luffy and his swashbuckling crew in their search for the ultimate treasure, One Piece!

As a child, Monkey D. Luffy dreamed of becoming King of the Pirates. But his life changed when he accidentally gained the power to stretch like rubber...at the cost of never being able to swim again! Years, later, Luffy sets off in search of the "One Piece," said to be the greatest treasure in the world...

Luffy's pirates thought they were just stopping in for a quick bite...but now Luffy's been made a busboy on Baratie, the oceangoing restaurant, and it turns out some of the worst-mannered pirates on the Grand Line are just dying for a meal.

Always one to look on the bright side, Luffy sets his sights on Sanji, the smart-talking, skirt-chasing assistant chef on the Baratie, as the Merry Go 's new cook. But it'll take more than a vicious pirate battle and a little sweet talking from Nami to convince him to leave the Baratie and join Luffy's team. His oath to feed any and all pirates in need keeps getting in the way. The question is: what do you do when the very same pirates you just fed now want to serve you up for dinner?