The story line was good, and the struggles were realistic. Even most of the characters were alright, but I had to rate it low for one character: Rin.
There is no character in all of manga history that I disliked more than him. I get what the author was trying to do; s/he was trying to garner the sympathy for someone in an unfortunate situation of fate, caught unawares by circumstance. But god if I didn't cringe every time he chased after SOMEONE ELSE'S BONDED MATE. They weren't just dating. They weren't casual. They've been LIFE PARTNERS and they were bonded despite the adversity they faced, and here comes Rin going, "oh look at my heart beating extra fast and me feeling tingly in my unmentionables. Let me just RUIN a happy union because I'm a completely selfish fuck and instead of finding my own happiness, let me just take away someone else's." Nah. Miss me with that shit.
And if Rin wasn't so present in the entire story, maybe I would have rated it higher, but his simpering and endless crying was practically on ever page of the chapters following the bonding of the main two characters. I just couldn't. I completely skipped the last chapter of him finding actual happiness the way everyone else should have: in a healthy reasonable way.
I couldn't stand him. 5.66 out of 10. And that's on a good day.
Kudos to the author on the plot and the effort and the art. Everything else was well done.