Have to admit that I was only visualising the OP starting at Narita Airport and perhaps wanting a cheap, direct route FROM Narita Airport to Asakusa.
My anticipation was that they would look for the departure time on Hyperdia. I mentioned (Tobu) only because that is the way to identify the route on Hyperdia, it’s not easy to find information on this route elsewhere.

I confess that I hadn’t fully considered the reality of getting back to Narita Airport from Asakusa.
And that’s why I post publically and avoid giving advice via PM. It seems impossible to consider every eventuality for everybody’s situation and from every person’s point of view.

No matter. It’s not the most pleasantly arrived at resolution, but between us we seem to have covered everything. It’s a shame that all this Data won’t read in the friendly way it was supposed to be conveyed.