"Ryuu" is a reincarnated modern human in a different world where he finds himself as a slave. However, once he recalls the knowledge from his previous life, his magical abilities are also unlocked. He rapidly gains strength, outpacing other slaves, and effortlessly overcomes formidable foes, rising to become the strongest gladiator among slaves. Ryuu is purchased by the noble Juller. The Juller Family, who viewed slaves as a source of power, sought to possess an exceptional slave. The first command given to Ryuu as a slave was to "seed" a stunning female slave...! I'm a slave, but incredibly free! This otherworldly fantasy begins from the lowest tier but promises an unlimited future, kicking off with a BANG!