Totally forgot about the part where they grew up so isolated they didn't even realize Azumi was a girl (or, for that matter, that there is such a thing as a girl ^^).
Also, yeah, that deathmatch was pretty stupid. Spend 15 or whatever years on training 10 elite soldiers. Then butcher half of them before you even get started, just because. And don't mind the risk of them killing you instead and just living happily ever after instead ...