Politics in the Empire has always been a deadly affair. With war limited in scope, negotiations must take up all the slack. If the Emperor declares that an issue must be decided in his court and one of the parties does not show (because their ambassador is dead, frex), it is both a grave insult to the Emperor and an automatic loss.
As well, insults cannot be suffered while in court as the resulting loss of face would make the offended party a laughing stock. There is only one answer to a loss of face: death, either of the insulter by duel or of the insulted by ritual suicide. What this means is that the diplomat with the slyest, subtlest manner of shitting on people has a pretty strong edge.
The other strong edge in court is being backed up by a killer duelist. Then you can choose to take anything as an insult an have your duelist challenge the “offender” in your place.
Neither of these options are very honorable. It’s certainly cool to walk softly and carry a big stick, but throwing around your power is not socially cool and probably not good for your health either – it’s a good way to make enemies. Calmness in the face of all adversity, honesty (or seeming to be very sincere), and eloquence are the greatest virtues of court.
Obligation, though, is the strongest “soft” power in court. The giving of gifts is a valuable weapon, because gifts cannot be refused without dishonoring the giver and a gift, once accepted, obligates the receiver to repay it in kind. Clever courtiers can manipulate this system by knowing who owes who what favors and giving the perfect gift at the right time. If a clan courtier can reach his enemy’s court, he may even be able to stop a war by calling in the right favors and giving the right gifts. How a clan’s courtiers manipulate the web of obligations can define that clan’s political power.
Sincerity is extremely important to the Empire, being a tenet of Bushido. While adjudicating court issues or deciding matters of law, how sincerely a victimized party can express themselves is often more important than direct evidence. In the law science of the Empire, testimony is absolutely the most important consideration.
Another facet of court is the taking of hostages. Often, to cement a peace treaty, the daimyos of both clans will give each other their children as hostages, to be held for a number of years. While being held hostage, a child will grow up as a member of that clan, given as much respect as a child of a daimyo should. Upon returning to his or her home clan, the child may have enough obligations, respect and awe for the former enemy that no further wars will be fought. Or, the child may have been spending all the time doing stealthy reconnaissance work for their clan, but that is rarely the intention.