[jason taylor]

How about a modification of Johney's system. There is a multi layer nobility. The first is constructed by adoptees or fosterlings of the Emperor. These change their primary surname (in the event of a political adoption a secondary surname remains for the sake of the blood familie's dignity). They are the ones picked for the highest of positions. This might include the Imperial Harem, the Chief Bodyguards, the taster, the great mandarins, whatever.

Below that is a nobility based on those who have relations who were tagged at one time or another. These are usually subalterns and sometimes general officers in the naval and military forces. As well as lower level mandarins and judiciary.

Below that is the gentry which provide Samurai/chivalry/whatever name you give the warrior caste. As well as the local constabulary and emergency services. These would be clients of the various nobility and sometimes recreate in miniature the system designed for the whole empire.

Being married into or having a child adoped or fostered in the Imperial clan is considered a promotion, both by the dynasty and the individual. Having multiple adoptions is a minor promotion beyond that.

To marry or be adopted by directly by the Emperor is the highest honor. To be given a sibling or cousin less so. There is a subtle series of distinctions based on how close one gets to the Imperial line.