@Lxminous Well... I try to see this from a middle point. Most of us we have a western mind. For example, I am from Spain, and I understand that part of the behavior of this story is driven from Japanese mentality where roles are more rigid than here.
There, relationships are more established by titles and rules, here, by context and facts.
For a western individual, it is common than see in every other individual a potential friend. A friendship is built around trust (well.. that's worldwide I guess) so It's common to approach with light excuses of ask minor favors so you help each other or do some friendly talk and share more and more good moments so that potential friendship turn into a real one.
BUT... for Japanese people, at least from a more traditional way of doing things, they separate the roles very clearly. A coworker is a coworker, a friend is a friend, a family member is a family member... Doing new friends is very difficult for Japanese people and they are very close in these things.
They don't declare as "X", see this as friend or girlfriend/boyfriend until it is very clear... and mostly established and formally declared by both sides.
From our side... we have sometimes problems to define what kind of relationship we have between each other.
Ask to a couple that hold hands... "what is your relationship exactly?"
Well... "Friends... with benefits? Temporary lovers? Boyfriend and girlfriend with no wedding in mind?...". Sometimes we even don't know how to define it... But we know clearly what is it.
We trust each other... we like and enjoy to be together... we have sex... and we expect to be faithful to each other (or not) after talk about that.
Yes... It's complicated to understand different ways of thinking. And I guess this story is based on the most traditional way of thinking of Japanese culture (although new generations have a lot more western mentality).
See this story from out perspective of thinking is very frustrating because it's very clear that they both past the point of friendship long ago. Like I said before... mostly in chapter 56 they both behave towards each other like friends. We are at chapter 157!