I'd look at the issue from the reverse angle:
If I was in an accident falling in a coma for many years, would I want my partner to suffer like a dog, truthfully waiting for me all the time? Heck no, I wouldn't. It would be terribly selfish to do so. And heck, we SAW Takayuki falling apart. Would you demand that from him/her?
Consequently, in my eyes you'd be a horribly cruel and selfish person to do so. If I was in Haruka's shoes, I'd try my hardest to get together after my coma - but I'd be horrible to blame Mitsuki for moving in after a full year. Keep in mind that in the anime, Haruka did NOT blame her.
From the positive angle, Mitsuki for me. She tried harder and suffered longer. It's extremely unlucky and unfair for Haruka, but... sorry. Most people damning Mitsuki have a strangely selfish and warped outlook on things (absurd-esoteric stuff like blaming her for Haruka's accident). Honor Haruka's graceful sacrifice in the end and her wish for a forgiving reunion via her "Hontou no Takaramono" book, instead of making this an "he's MINE!!!" shouting match
