Aido defently, especially after seeing Akatsuki's anime design. ^^;
Kain is more mature and he rocks for it, though low half he aint really a sense of humor, and the opposuite implys for aidou to, the downer for aidou is he... well.... dislikes yuki ;-; and for god knows what reason? (maybe it is like what the poster said before and because he likes her? though there is no other answer i can think of and its not like we have seen any hints coming from his side of feelings.) on the other hand he is hillerious.