Was just there two weeks ago.
The haul from the 40 gates takes
forever. About 10-15 minutes.
Unless you speak Japanese, the young ladies at passport control won't say a word. Even if you do, they probably won't.

They just load in your info and apply your stamp.
The Immigration agents speak clear English. They ask a handful of questions (how long you are staying, etc. - mostly stuff passport control asks at other countries) and usually just send you right through without bothering to look at your bags.
Tokyo doesn't even try to make it hard, now.

All the signs are in English, all the onboard and station annoucements for the trains are in English, the Friendly Limousine Bus folks speak English. It's a cakewalk even for someone with no Japanese to get around.