Ambition or Hubris?

There's a senior manager position open within my department, and it doesn't look like the seat will be filled any time soon. Given some recent developments at the day job, I'm seriously considering talking to some of the executives to ask for that position when I'm in Tokyo next Tuesday. That said, this isn't how promotions are done within the company, and it's not something that would be openly accepted by everyone. Should I do this, or is it just a delusional idea that has manifested from my own hubris?