Kazuki would probably have a somewhat easy life with Kuriko.
Since she is rich. Though she does appears to think about her own benefit first. And wants his genes to give her future
baby a power boost that would benefit her family in the future and secure their powerful possition.
She likes to manipulate people to get her way. And will most likely will make the descissions for Kazuki. There is also
that little ghost that might disrupt the relation because she doesn't want Kuriko to forget about her. There
won't be any true love anytime soon because of this.
Yuuna is the most caring and gentle... as long as Kazuki isn't near any other seductive women. She is determined to
keep her promise to marry him and does her best to please/ protect him. A good cook as well. If only she wasn't
extremely jealous and possessive. Those character flaws might just kill Kazuki off someday. She would be the best choice
if they where on an abandoned island. ;)
Rin does indeed have the most manners and is the most polite.
But she was forced to train to be an honourable and polite fighter and didn't really have a chance to enjoy her
childhood.
She really doesn't like the fact Kazuki is so weak, if he would go with her, Kazuki would have to endure a lot of
training and her terrible cooking. She isn't open about her emotions and has to learn to have a good time. A
relation that might be hard at first for Kazuki, but may pay off greatly if they really open up to eachother.
I think he would have it best with his other childhood friend Yamase. She is simply the most normal compared to all the
other girls. She would try her best to keep Kazuki's flaws in check by telling him what to do. That might make her
a bit bossy. But since Kazuki is too kind for it's own good, it's not such a bad thing. She isn't the
jealous type also, so Kazuki would last long under her care.