Responses

Well, from what I gathered so far, its pretty common for the prince/princess to marry the
tribe generals or their family[ Tae-jun courting Yona or *spoiler maybe* later on in the manga others suggesting Lily for Queen] .
So compared to them Soo-won is still of higher rank since he's Yona's cousin. So the lower rank thing is actually not a problem is what I meant to say :P
Wait did the summary change? Was it always this and I never noticed?
Yona's not in love with a man of a lower rank tho??? He's of royal blood