Rebadan Kibou no Hana

An engineering professor finds himself transported back to the 16th century, where his astonishing knowledge of things hitherto unknown to the people of that period causes him to be revered as a holy being. The ruler of this land -- a spoiled young man completely unaccustomed to being refused even his slightest whim -- claims the hapless engineer as his own without hesitation. Initial resentments and misunderstandings aside, the two begin to grow closer to each other. [Official English Translation](https://read.futekiya.com/comic/617bbb80024b7)