Knew Amaris and Kouya will get together, it was the only option.
Zero choosing to leave the controlling yandare, muscle brain siscon Amaris and two faced (forced) Lilly that constantly abused him for chibis who liked him how he is was the only choice. They didn't even try once to keep him really welcome.
Kinda like the story, Zero has grown much, he started to even smile chapter by chapter and finally felt bliss at the "end".
Don't like the final ending, neither Grace, Lilly or Amaris changed, although they initially seemed to suffer from being separated, didn't see the reason why he didn't hesitate one bit when Zero was about to leave. They even immediately told him to "shut up" when he shown how little Zero care about people with no true respect to anyone.
It's better for the story if he stay with the chibis in blissful place and never came back, with "harem" reflecting finally how they treated him and move on with anyone else.
It would be a solid 9/10 but for the last part, maybe 5/10...