Upvote:-2
The information I got from the VFS was if your connecting flight is at the different terminal you need a transit visa. I would recommend you directly contacting the Japanese Embassy.
Upvote:4
You can transfer between T2 and T1 using an airside shuttle bus. (This is different from the landside shuttle bus between terminals that most people seem to know about.)
You can get the bus at two points in T2: at gate 80 in the satellite building, or at gate 70 in the main building. These drop off at gate 28 and gate 59 in T1, respectively. In each case you will go through security before boarding the transit bus. Follow the signs for "International Connecting Flights" to the transit security checkpoint.
If you haven't got a boarding pass for your next flight segment, go to the transfer counter first, to pick it up. It is next to security.