The thing is she could have let those unsavory elements be there and just be a comedy like it was in the beggining. It's not the first time I read a manga that makes comedy of the concept of bimbos mrmagooing themselves into sexually harrasing by sleazy scumbags.
The problem is the awful bait and switch into a drama aiming for a cheap emotional turmoil and growth just for the ending because you got a big head and think you are hot shit. You either make the bait and switch into something worth the switch or just keep doing your shitty ecchi, don't make this. Less you do this only to in the end introduce us into a Tim and Eric sketch about "the genius of bed scenes" without the comedic tone.
It's so fucking incredible the author didn't realize how innately funny "the genius of bed scenes" character is, being a buddha level cuck who takes his inner turmoil of being played and cucked and transforms it into breathtaking cinematography. It's a million dolar idea joke... and she plays it straight. Fucking hack of a writer, man, I tell you.