You're in a arranged marriage because your parents forced you. The relationship was pretty much public because the youngest and oldest children of the two of the most powerful families were "dating" and so "in love"

Keeping the fake image that they were "so in love" 5 months later the wedding happened, but they can't stand each other at all, they were dating other people before the marriage, so everything was a huge lie and a montage

Time skip

First day of the honeymoon in Hawaii

"So...Is he coming or something?... Because Mizuha is definitely coming to see me"