Naishi: My Favorite Mechanism

About Naishi, from BoardGameGeek:

In Naishi, you will seek to improve your Japanese state as efficiently as possible. However, you will not be free to change the positioning of your cards at will. You must replace the cards in your hand and in your tableau with cards from the central river while respecting their positioning. You will also have the possibility to send your emissaries to reorganise states, create new opportunities or force your opponent into a trade