I don't think they should get together, Yamato is a nice boy and will be an amazing man but Yakumo already has a level of experience in life that even 10 years in the future he won't have the emotional knowledge to support Yakumo ( remember 10 years in the future, yamato= 24, yakumo= 38 ). I won't say i want Yamato to get with Rui, she is a little too high strung, but she can change who knows.
My point is i like the shenanigans of this manga and I like seeing those two interacting, but not every romance story has to end with the characters together, no matter how we think they should, to me this story is about healing and learning.