Disclaimer: Don't own Naruto. Never did never will. Sucks I know! New story and gets better!
It was a mans world. Men ruled and made the decisions for everyone. Women were to be civil, obedient, kind gentle spirits that obeyed both their parents (AKA father) and/or husbands commands or wishes. They were to cook and sew and give birth to all the little heirs the man wanted. A mans world. But soon its all about to change.
Now lets focus in on were our story begins. The ninja village, The Hidden Leaf Village.
About 3 generations back from the current children, 3 ninja rose above everyone else. The three legendary ninja, the Sannin; Orochimaru, Jiraiya, and the least accepted, the women named Tsunade. Now her teammates had no problems with her, unfortunately the rest of the village did (the men and some women in some cases). It was atrocious that a women could rise above everyone. It simply wasn't done. As soon as she had enough training to survive on her own, the kind Hokage (the 3rd), sent her off so the villagers couldn't harm/kill her, which they were likely to do soon.
Not long after she had left, Orochimaru, abandoned the village as well (though for his own personal reasons), leaving only Jiraiya who soon became fed up with the villagers antics how women were below them (he's a perv but he also has enough smarts to know that women were equal to him in every way), and went off on his own journey, to gather information and to write his hentai books.
Back to Tsunade
As soon as she left the village she traveled on her own, learning more and more jutsus and becoming even more powerful than before. She hated men for scorning her so. She hadn't done anything to them, but lowered their own pride. snicker. She soon became known both for her strength, jutsu, medical jutsu, you name it. She was powerful, proud, and women. And she liked it that way.