madoka's dominating acts wrren't bevause shr was a domme. That was her lashing out emotionally and sexually - thr case where a sub plays around and acts likely a brat, instigating the one they want to punish them. Kakiguchi was pretty oblivious, and hapless enough that the chance for him to actually fulfill the role of dom was rare, and it was only when madoka truly crossed the line - or deus ex machina coincidences - that he did step into the role, despite him clearly having a dark side that wants to "twist" his partner. Of course, nobody is truly limited to only the one fetish, so with their chemistry and ridiculously high sexual tensions and situations, they learned a few new aspects of their sexuality along the way.
Again, this was something that, had fate not conspired against them from so many angles, they could have developed a deeper relationship, had time to open up more and come to understand each other, and created a happy ending for themselves. But fate gave them the boot, they needed more time to develop and mature together.
Now, i wish that they had been given those chances. This story would probably be at least another three or four books long just to get to any sort of happy ending. But that wasnt the point of this story. This story was a glimpse into human nature - just a small crack in the wall. Life rarely has the chance to reach an agreeably clean ending before it gets cut off. Countless relationships fail to flourish because they dont get the opportunity to do so. Humans are fragile, and we put up powerful walls because of that, and then we're too occupied dealing with the world around us to focus on the things that matter. We're too oblivious and ignorant of each other's thoughts and feelings to communicate and develop together as best we could have.
This manga, whatever the hell anybody thinks of its contents and material, is something you all should be reading between the lines in. It'll help you understand what being human is just a little bit more, and maybe even give you the oush you need to open to one another. Because nobody wants to be yhe miserable guy reminiscing and fantasizing alone forever with just a worn out doll shaped like the one we loved most. And nobody wants to get run over by a train just when we finally got free of the shackles on us and mustered up the courage to grab an opportunity before it slips away forever.