The connection at HND was smooth. T1 -> T3 with the free shuttle bus and less than 10 minute wait at security.
First stop is the brand new AMEX Centurion lounge.
When I arrived, there were no other guests and the whole staff assembled to bow at the entrance. In general, alll the staff is extremely nice.
I was informed that entry is only possible three hours before departure (it was four hours for me) but was let in after showing the boarding pass of the flight from CTS. So it seems, the entry rules are in line with other AMEX Centurion lounges.
The lounge gets a little bit busier now, but still fairly empty. I guess it will need some time until people know about it. The space is not very big and I can imagine it gets crowded in the future.

To the left there's a small corner with sweets and a coffee machine. All types of seating are available, little nooks with a view, benches, tables, small chairs, ...

To the right is the bar area and behind it the restaurant. All very nicely designed and the natural light makes elevates it compared to, for example, the LHR Terminal 3 Centurion lounge.

There's a menu of "signature" cocktails. I started with the Japanese Garden which was very "delicate" and not very strong, still delicious.

In the Restaurant area there's a chef who prepares beef sliders and Ramen. The promised Sushi was not available today, maybe they have cut it already or switch around meals?
All the food is nicely presented and what I tried was good.