Captain Ruka is a handsome, dashing man who commands Shalomar Naval Base when Kozue is absent, which is frequently. Ruka attended Marching with Princess Kanna, and has apparently become quite intimate with her (and she with him), having been seen together in each other's presence several times since the holiday in question.
Ruka Tsuchiya was born in 1241 AY, the seventh son of one of the merchant families of Amber, and as such was sent into the Navy at an early age so that he wouldn't starve or be a burden on his family. Fortunately, he had a knack for the naval life, and rose slowly but steadily in the ranks of the Amberite Navy, riding out the Succession Crisis, raids against the Shalomar Pirates, various wars against the Sea Peoples, and the Melnibonean War, to his current position as the second-in-command of the Shalomar Naval Base.
Ruka is known to have accompanied Prince Lucien and Princess Kanna in some mission regarding the Bloc. He is currently working on getting the Shalomar Naval Base back into shape after the Black Unicorn Amber attacks, though the providing of a fleet from Jade has helped in that regard.
Ruka's parents are still alive (albeit elderly), as well as many of his siblings, and he has several nieces and nephews. It it unknown what they'll think of the fact that he and Kanna are now an item, though it's sure to be memorable.
Despite persistant rumors, his forelock is neither a Chaos Monster, a point item, or out to rule all Space and Time.