18+ Kikenbi Neratte!? Haramase Oukoku

There was once a faraway land.
Born a lowly vagrant, the protagonist hid away in the streets of squalor. One day a royal parade passed, and with it the beautiful princess Celena. Inspired, he became a servant of the castle, but was in the dungeons. Then another beautiful girl offered him a chance to work in the house of nobles...

And with that first step was born the man (still you!) who would shake the world. The king of pregnancy.

(Source: dlsite)