@diidlydoo
Most relationships will have bad times, but not everyone has anger management issues. Daytime television, soap operas, romcoms and dramas, and reality TV should not set the bar or be a role model for personal relationships and problem solving.
A strong relationship isn't about the absence of hardship, but the the ability to work together in dealing with hardship. But when it comes to hardships, ones that are wholly caused by one of the people in the relationship and are avoidable are of special note.
A sign of a strong relationship, romantic or platonic, is when you can admit your faults and take steps to manage and minimize those faults. When it rains, you build a roof and take an umbrella, when there are earthquakes you change the building code, when people have shortcomings they create social systems and practice to minimize the effect of those shortcomings. Part of being human is being able to learn and predict, you don't need to wait until your kitchen is on fire to go out and buy a fire extinguisher.
Speaking of the last two chapters specifically, I get that the two of them are basically still children and act like children. (which, if I'm honest, makes the whole marrying a child thing more uncomfortable when before it was easy enough to squint a little and ignore it.) So it's not like it's unexpected or unnatural for people to act like that, I just don't think such childish behavior is really praiseworthy.
I think for me, the real irksome part is that they didn't really do anything to resolve the problem, things just sort of worked out for the best on their own. Kayo is worried because she thinks Chiru is better than her, and Suzu just so happens to prefer people who aren't better than her. Then when she comes back, there's no working out how to prevent or reduce the same thing happening in the future, they just say as long as she comes back then it doesn't matter. (And I'm not even going to get into how messed up it is that Kayo was born into a subservient lower class to begin with, just gonna try to squint a little and overlook that too. Healthy relationship indeed.)
So yeah, I hope this drama is over and we can get back to the fluff that is the reason I'm here in the first place. An entirely selfish wish, I readily admit.