Sumire Kanzaki, Heir to Kanzaki Enterprises of Ember, and Ambassador to Amber from Ember.
Daughter of one of the richest families in Ember, Sumire and Kanna have been "friends" ever since childhood. Using this term may be stretching the point, however, given how much the two have argued over the years, with Sumire berating Kanna's habits as being improper for the Queen's Daughter, while Kanna continually commented that Sumire was too stuck up for her own good. Indeed, it's a mystery to many why the two haven't throttled each other by now, or worse. Despite that, they work well together when the opportunity presents itself, though this hasn't occured recently due to Sumire's appointment by Corrine to the ambassadorship two years ago.
This doesn't stop them from requesting the occasional Rose Duel, however...
Sumire is known to be competant in sorcery, and often wields a naginata known as Koucho-no-Tsubasa (aka "Butterfly's Wing") in combat. She recently accompanied Kanna on the rescue of the Tenjou Trio, and after plummeting from a dispelled zeppelin and being knocked unconcious, she has decided that staying back in Amber for a while would be a Very Good Thing. And don't ask about the ninjas from shadow who are trying to capture or kill her. Just don't.
Sumire recently led a large army of Ewoks to capture the Kanawa Corporation logging base on Endor. The operation was a rousing success, although Sumire seemed somewhat embarassed by her troops.
It was recently discovered that Sumire is the daughter of Drake by Nabiki, and was placed in Ember at birth to keep her safe from Drake's enemies. This revelation has forced her to break off her on / off romantic relationship with Kentaro for what will probably be the last time.