In the World of Sword and Magic as Space Marine - Chapter 87: In Midnight Clad

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

In a world where Beast Tamers command respect and wealth, Kai is nothing but a street rat, scraping by on the streets of Ashenford.Orphaned and despised by townsfolk, he's learned to expect nothing more than cold stares and cruel words.His life takes an unexpected turn when he stumbles across an injured beast deep in the wilderness.Kai nurses the creature, forming an unspoken bond that will alter his fate, and he begins to see the harsh realities of a world ruled by power, status, and secrets.

Oosuki Masato is an ordinary high school boy who is magically transported to an alternative world, but for some reason his doting, over-protective mother comes along as well.