User blog comment:Fintin/Haki/@comment-2015213-20100703143012

Should there be any kind of training of Haki then it should be just Luffy training Haki all by himself, sure Hancock,Marguerite or Jinbei(he may or may not have it but he seems to be that kind of person who would know about it and everything it can do) could give him instructions on how to use it but that should be it.