I have an Air Asia flight to Haneda, Tokyo's smaller airport. I then need to get to Narita. What public transport options do I have?
(Assume during the day, as I'll likely nap in the airport until services start running in the morning).
You can take the airport shuttle (Airport Limousine Bus) direct from Haneda (International Terminal) to Narita (Terminal 1 then Terminal 2) for 3,100 JPY. It comes fairly regularly (roughly hourly) and takes around 95 minutes. The earliest departure is 06:25.
Alternatively you can take the train. The best route depends on time of arrival, but your main options will be:
Total route cost: 3,600 JPY.
Total route cost: 1,760 JPY
If you want specific timings to plan your train journey and see which of the routes is better for you, check out the always-useful Hyperdia website.
Having taken the bus I strongly recommend it - very comfortable, spacious and air-conditioned. What's more, you can see some incredible urban views on the elevated express ways and drops you right at departures at Narita.