4 hour layover in Narita Airport, is this enough time to explore?

Question:

I'll be flying to Seoul in July and have 4 hours to kill and would like to do some exploring.

If it is enough time, what needs to be done to be able to leave the airport and come back?
What can I do with my carry on luggage?
What fees are there if I leave the airport and how much will transportation in the city cost?
I'm traveling alone, will it be safe to explore in Narita by myself (i'm female)?
Any recommendations of what to do?
Is there WiFi in Narita? Hows the availability and whats the cost?

Exploring Narita is far more appealing than trying to kill time in an airport.

Answer:

It's not enough time if you mean only four hours between flights. Remember you have go through security just to enter Narita terminal and Japan has exit controls. It all takes time. By the time you got to Narita city station you would have to turn around and go back. That being said, there is a place where you can store your things at the airport, and Narita temple and its museum are worth a visit.