Manga by author Leafy

Akito wants the stereotypical isekai experience and so he summons himself to another world, however things don't quite go as planned. He's the same unskilled loser that he was before. He can barely scrape together enough money to eat. One day a cute girl approaches him with a contract to join her party. He can't read what it says, but ends up being forced to sign it anyway. What's the worst that could happen?

A story about a married couple who've abstained from sex until their wedding night. But on their wedding night, the wife turns into a little girl.But that doesn't stop her from wanting children.