Hege Riise’s side face Australia in their women’s quarter-final after topping Group E with seven points.
Riise was not initially due to manage the team in Japan but former England boss Phil Neville, who was pencilled in for the job, joined Inter Miami in January.
Team GB are unbeaten at the Tokyo Olympics after beating Chile and Japan before drawing with Canada on Tuesday and Riise is loving the unexpected opportunity.
The Norwegian said: "It's been a privilege, we have been working on the culture, who are we, how do we want to be seen, how do we want to perform?
"All the players buy into that, they know what it will take for us to go all the way. I feel we have done a great job, now it's the knockout stage and it's about how brave we are.
"I feel we are in a good spot right now, the players feel comfortable, they feel we are doing the right things. I'm excited for the game."
Striker Fran Kirby could be handed her first start of the competition after recovering from a knock she suffered in training before the team flew to Japan.
Kick-off time and venue
Team GB vs Australia gets underway at 10am BST today.
The match will be held at Kashima Soccer Stadium in Kashima.
How to watch Team GB vs Australia
TV channel: The match will be shown live on BBC One via the BBC Red Button for free for UK viewers with a TV licence. The quarter-final will also be shown on Eurosport 2 and Discovery+.
Live stream: The match will be available for free online on the BBC iPlayer as well as the Eurosport Player.
Additional reporting by PA.