Can I marry a girl without her guardian?

I'm in a haram relationship with a girl since 1 year and now we wanna make it halal but our parents won't accept because we are not enough aged for getting married. But we love each other so much and we can't live without each other and we got really close to each other. So now my question is can I marry her without her guardian's permission if I can then I'll continue our relationship by making it halal and after getting enough aged we would got married fully from the families willing too. I really hope you would answer my question.