Arrow always saw the world in a practical way. He ignored impractical emotions of himself and others. His goal in life was to have a better understanding of the laws of the universe through the study of science.

But...

Due to an accident in a physics lab at work Arrow's consciousness crossed time, space, and possibly even dimensions. He became Arrow, a pink-haired teenager with a reputation of being a cheating waste in a land of magic. Arrow, now Lopi, must find a place for himself in this new world with no scientific community. He has to avoid being killed by other nobles, by his family, by magical beasts, or by any magical or martial arts practitioner that is stronger than him(currently 99.98% of practitioners over the age of 8).

Oh, and this is slow bl, which is great because the mc has a friendly relationship with many different women of a variety of ages and it never turns into a sex harem.