No, it's not. How do you think abusers who get their victims to trust them are in 'failed' relationships if that were the case?
I don't think you worded your question well. The relationship between an abuser and their victim is NOT founded on mutual trust. The abuser doesn't trust the victim and any trust the victim has for the abuser was developed out of fear and a need to survive. I do consider such an unhealthy relationship to be a failed relationship.
I completely agree. Honesty can not save every relationship, but without it, you're increasing the chances of failure
I love how this story depicts their relationship. This manga just ilillustrates the importance of being open and honest with yourself, and your partner. While the truth can be hard (as in the case of Sanada when he realized he was gay) it is necessary. And in the present, if the two characters were honest sooner, they would've saved themselves a lot of heartache. Any relationship that is founded on mistrust and assumptions is doomed to fail