Originally Posted by
armagebedar
A
shuttle bus runs between the terminals in 10 minutes, so that part is easy. However the real issue is how long immigration takes, as you must go through immigration for an inter-terminal transfer. If you can get through in under 20 minutes, then you should have no problem.
No. OP does NOT have to go through immigration.
There's a shuttle bus for connecting passengers within airside. For more information, you can visit:
http://www.narita-airport.jp/en/guid...ter/index.html
You should contact your airlines so they are aware of your situation. The airside shuttle bus is not that frequent