At the end of No More Heroes, Jeane reveals her backstory is allegedly "too terrible" and will "jack up the age rating of the game". She also makes a reference that "you don't want this game to become No More Heroes Forever, a joke about Duke Nukem Forever's long development period. She then proceeds to tell her backstory at a sped up speed so that it is absolutely impossible to understand what she says. Slowing this down reveals a very horrible story:

"You are my half brother. You know that manga called Miyuki? The Japanese one. Well, it's like that. Your father abandoned my mother to run off with your mother. It broke her heart beyond repair. She killed herself. Knowing I had nowhere to go, he took advantage of me. Ever since I can remember, he molested me. We lived in this rotten apartment... And I was his slave. Every day I cursed his soul. I swore that I would kill him one day. But cursing didn't change anything. That's when I decided to become a killer. With no money to pay for training, I paid with my body. But to you, I bet that son of a bitch looked like a hard-working family man. That was all an act. He didn't give two shits about cleaning up my life so I decided to clean it up myself. That's why I do what I do. And I got what I wanted. Killing him in front of your very eyes. That's my story."