I'm kind of amazed at how Shuinta managed to write a NTR story without actually having NTR.
Frankly, I'm incredibly dissapointed at how weak Ruki is. The whole story was pretty much seeing her identity and ego being broken down little a little until she became nothing more than a shadow of herself. She went from a strong and well meaning woman into someone that is defined by her relationships.
She got Sachan on the end, but getting a lover by saying "I don't care about anything as long I'm with you" is never worth it. After all, the most basic rule on relationships is "you can't love anyone if you don't love yourself first".
All in all, this was just a depressing story fron beginning to end.