Please help me find a manga I read 4-5 years ago, it was a visual novel first.
It starts with some 20 something dude being transported to a fantasy world, a big breasted dark skinned redhead queen wants him to marry him to be her puppet king because he has noble blood for reasons.
He accepts, returns him to his world, he picks up a few things, sees his parents one last time, quits his job. He then goes back to the fantasy world to marry her and he ends up being useful with some knowledge because they live with ancient/medieval level technology.
He brings his laptop and an electric generator, and uses spreadsheets to help her calculate taxes for the nobles at some point.